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621 lines
25 KiB
Go
621 lines
25 KiB
Go
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package expression
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import (
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"fmt"
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"strings"
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"github.com/aws/aws-sdk-go/service/dynamodb"
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"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
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)
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// ValueBuilder represents an item attribute value operand and implements the
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// OperandBuilder interface. Methods and functions in the package take
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// ValueBuilder as an argument and establishes relationships between operands.
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// ValueBuilder should only be initialized using the function Value().
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//
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// Example:
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//
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// // Create a ValueBuilder representing the string "aValue"
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// valueBuilder := expression.Value("aValue")
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type ValueBuilder struct {
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value interface{}
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}
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// NameBuilder represents a name of a top level item attribute or a nested
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// attribute. Since NameBuilder represents a DynamoDB Operand, it implements the
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// OperandBuilder interface. Methods and functions in the package take
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// NameBuilder as an argument and establishes relationships between operands.
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// NameBuilder should only be initialized using the function Name().
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//
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// Example:
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//
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// // Create a NameBuilder representing the item attribute "aName"
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// nameBuilder := expression.Name("aName")
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type NameBuilder struct {
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name string
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}
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// SizeBuilder represents the output of the function size ("someName"), which
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// evaluates to the size of the item attribute defined by "someName". Since
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// SizeBuilder represents an operand, SizeBuilder implements the OperandBuilder
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// interface. Methods and functions in the package take SizeBuilder as an
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// argument and establishes relationships between operands. SizeBuilder should
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// only be initialized using the function Size().
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//
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// Example:
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//
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// // Create a SizeBuilder representing the size of the item attribute
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// // "aName"
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// sizeBuilder := expression.Name("aName").Size()
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type SizeBuilder struct {
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nameBuilder NameBuilder
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}
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// KeyBuilder represents either the partition key or the sort key, both of which
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// are top level attributes to some item in DynamoDB. Since KeyBuilder
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// represents an operand, KeyBuilder implements the OperandBuilder interface.
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// Methods and functions in the package take KeyBuilder as an argument and
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// establishes relationships between operands. However, KeyBuilder should only
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// be used to describe Key Condition Expressions. KeyBuilder should only be
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// initialized using the function Key().
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//
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// Example:
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//
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// // Create a KeyBuilder representing the item key "aKey"
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// keyBuilder := expression.Key("aKey")
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type KeyBuilder struct {
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key string
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}
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// setValueMode specifies the type of SetValueBuilder. The default value is
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// unsetValue so that an UnsetParameterError when BuildOperand() is called on an
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// empty SetValueBuilder.
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type setValueMode int
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const (
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unsetValue setValueMode = iota
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plusValueMode
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minusValueMode
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listAppendValueMode
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ifNotExistsValueMode
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)
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// SetValueBuilder represents the outcome of operator functions supported by the
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// DynamoDB Set operation. The operator functions are the following:
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// Plus() // Represents the "+" operator
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// Minus() // Represents the "-" operator
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// ListAppend()
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// IfNotExists()
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// For documentation on the above functions,
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// see: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET
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// Since SetValueBuilder represents an operand, it implements the OperandBuilder
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// interface. SetValueBuilder structs are used as arguments to the Set()
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// function. SetValueBuilders should only initialize a SetValueBuilder using the
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// functions listed above.
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type SetValueBuilder struct {
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leftOperand OperandBuilder
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rightOperand OperandBuilder
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mode setValueMode
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}
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// Operand represents an item attribute name or value in DynamoDB. The
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// relationship between Operands specified by various builders such as
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// ConditionBuilders and UpdateBuilders for example is processed internally to
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// write Condition Expressions and Update Expressions respectively.
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type Operand struct {
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exprNode exprNode
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}
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// OperandBuilder represents the idea of Operand which are building blocks to
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// DynamoDB Expressions. Package methods and functions can establish
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// relationships between operands, representing DynamoDB Expressions. The method
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// BuildOperand() is called recursively when the Build() method on the type
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// Builder is called. BuildOperand() should never be called externally.
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// OperandBuilder and BuildOperand() are exported to allow package functions to
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// take an interface as an argument.
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type OperandBuilder interface {
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BuildOperand() (Operand, error)
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}
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// Name creates a NameBuilder. The argument should represent the desired item
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// attribute. It is possible to reference nested item attributes by using
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// square brackets for lists and dots for maps. For documentation on specifying
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// item attributes,
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// see: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Attributes.html
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//
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// Example:
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//
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// // Specify a top-level attribute
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// name := expression.Name("TopLevel")
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// // Specify a nested attribute
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// nested := expression.Name("Record[6].SongList")
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// // Use Name() to create a condition expression
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// condition := expression.Name("foo").Equal(expression.Name("bar"))
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func Name(name string) NameBuilder {
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return NameBuilder{
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name: name,
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}
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}
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// Value creates a ValueBuilder. The argument should represent the desired item
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// attribute. The value is marshalled using the dynamodbattribute package by the
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// Build() method for type Builder.
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//
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// Example:
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//
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// // Use Value() to create a condition expression
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// condition := expression.Name("foo").Equal(expression.Value(10))
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func Value(value interface{}) ValueBuilder {
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return ValueBuilder{
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value: value,
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}
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}
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// Size creates a SizeBuilder representing the size of the item attribute
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// specified by the argument NameBuilder. Size() is only valid for certain types
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// of item attributes. For documentation,
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// see: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.OperatorsAndFunctions.html
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// SizeBuilder is only a valid operand in Condition Expressions and Filter
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// Expressions.
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//
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// Example:
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//
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// // Use Size() to create a condition expression
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// condition := expression.Name("foo").Size().Equal(expression.Value(10))
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//
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// Expression Equivalent:
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//
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// expression.Name("aName").Size()
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// "size (aName)"
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func (nb NameBuilder) Size() SizeBuilder {
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return SizeBuilder{
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nameBuilder: nb,
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}
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}
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// Size creates a SizeBuilder representing the size of the item attribute
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// specified by the argument NameBuilder. Size() is only valid for certain types
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// of item attributes. For documentation,
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// see: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.OperatorsAndFunctions.html
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// SizeBuilder is only a valid operand in Condition Expressions and Filter
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// Expressions.
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//
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// Example:
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//
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// // Use Size() to create a condition expression
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// condition := expression.Size(expression.Name("foo")).Equal(expression.Value(10))
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//
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// Expression Equivalent:
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//
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// expression.Size(expression.Name("aName"))
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// "size (aName)"
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func Size(nameBuilder NameBuilder) SizeBuilder {
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return nameBuilder.Size()
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}
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// Key creates a KeyBuilder. The argument should represent the desired partition
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// key or sort key value. KeyBuilders should only be used to specify
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// relationships for Key Condition Expressions. When referring to the partition
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// key or sort key in any other Expression, use Name().
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//
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// Example:
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//
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// // Use Key() to create a key condition expression
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// keyCondition := expression.Key("foo").Equal(expression.Value("bar"))
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func Key(key string) KeyBuilder {
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return KeyBuilder{
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key: key,
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}
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}
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// Plus creates a SetValueBuilder to be used in as an argument to Set(). The
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// arguments can either be NameBuilders or ValueBuilders. Plus() only supports
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
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// NameBuilder must specify an item attribute of type Number.
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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// Example:
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//
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// // Use Plus() to set the value of the item attribute "someName" to 5 + 10
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// update, err := expression.Set(expression.Name("someName"), expression.Plus(expression.Value(5), expression.Value(10)))
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//
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// Expression Equivalent:
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//
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// expression.Plus(expression.Value(5), expression.Value(10))
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// // let :five and :ten be ExpressionAttributeValues for the values 5 and
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// // 10 respectively.
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// ":five + :ten"
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func Plus(leftOperand, rightOperand OperandBuilder) SetValueBuilder {
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return SetValueBuilder{
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leftOperand: leftOperand,
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rightOperand: rightOperand,
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mode: plusValueMode,
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}
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}
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// Plus creates a SetValueBuilder to be used in as an argument to Set(). The
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// arguments can either be NameBuilders or ValueBuilders. Plus() only supports
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
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// NameBuilder must specify an item attribute of type Number.
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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// Example:
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//
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// // Use Plus() to set the value of the item attribute "someName" to the
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// // numeric value of item attribute "aName" incremented by 10
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// update, err := expression.Set(expression.Name("someName"), expression.Name("aName").Plus(expression.Value(10)))
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//
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// Expression Equivalent:
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//
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// expression.Name("aName").Plus(expression.Value(10))
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// // let :ten be ExpressionAttributeValues representing the value 10
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// "aName + :ten"
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func (nb NameBuilder) Plus(rightOperand OperandBuilder) SetValueBuilder {
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return Plus(nb, rightOperand)
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}
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// Plus creates a SetValueBuilder to be used in as an argument to Set(). The
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// arguments can either be NameBuilders or ValueBuilders. Plus() only supports
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
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// NameBuilder must specify an item attribute of type Number.
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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// Example:
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//
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// // Use Plus() to set the value of the item attribute "someName" to 5 + 10
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// update, err := expression.Set(expression.Name("someName"), expression.Value(5).Plus(expression.Value(10)))
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//
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// Expression Equivalent:
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//
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// expression.Value(5).Plus(expression.Value(10))
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// // let :five and :ten be ExpressionAttributeValues representing the value
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// // 5 and 10 respectively
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// ":five + :ten"
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func (vb ValueBuilder) Plus(rightOperand OperandBuilder) SetValueBuilder {
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return Plus(vb, rightOperand)
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}
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// Minus creates a SetValueBuilder to be used in as an argument to Set(). The
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// arguments can either be NameBuilders or ValueBuilders. Minus() only supports
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
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// NameBuilder must specify an item attribute of type Number.
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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// Example:
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//
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// // Use Minus() to set the value of item attribute "someName" to 5 - 10
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// update, err := expression.Set(expression.Name("someName"), expression.Minus(expression.Value(5), expression.Value(10)))
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//
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// Expression Equivalent:
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//
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// expression.Minus(expression.Value(5), expression.Value(10))
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// // let :five and :ten be ExpressionAttributeValues for the values 5 and
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// // 10 respectively.
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// ":five - :ten"
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func Minus(leftOperand, rightOperand OperandBuilder) SetValueBuilder {
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return SetValueBuilder{
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leftOperand: leftOperand,
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rightOperand: rightOperand,
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mode: minusValueMode,
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}
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}
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// Minus creates a SetValueBuilder to be used in as an argument to Set(). The
|
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// arguments can either be NameBuilders or ValueBuilders. Minus() only supports
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
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// NameBuilder must specify an item attribute of type Number.
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||
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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// Example:
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|
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//
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||
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// // Use Minus() to set the value of item attribute "someName" to the
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// // numeric value of "aName" decremented by 10
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// update, err := expression.Set(expression.Name("someName"), expression.Name("aName").Minus(expression.Value(10)))
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//
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||
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// Expression Equivalent:
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//
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// expression.Name("aName").Minus(expression.Value(10)))
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// // let :ten be ExpressionAttributeValues represent the value 10
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// "aName - :ten"
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func (nb NameBuilder) Minus(rightOperand OperandBuilder) SetValueBuilder {
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return Minus(nb, rightOperand)
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}
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||
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// Minus creates a SetValueBuilder to be used in as an argument to Set(). The
|
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// arguments can either be NameBuilders or ValueBuilders. Minus() only supports
|
||
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// DynamoDB Number types, so the ValueBuilder must be a Number and the
|
||
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// NameBuilder must specify an item attribute of type Number.
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||
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// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.IncrementAndDecrement
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//
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||
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// Example:
|
||
|
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//
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// // Use Minus() to set the value of item attribute "someName" to 5 - 10
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// update, err := expression.Set(expression.Name("someName"), expression.Value(5).Minus(expression.Value(10)))
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//
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||
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// Expression Equivalent:
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//
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// expression.Value(5).Minus(expression.Value(10))
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||
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// // let :five and :ten be ExpressionAttributeValues for the values 5 and
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// // 10 respectively.
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// ":five - :ten"
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func (vb ValueBuilder) Minus(rightOperand OperandBuilder) SetValueBuilder {
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return Minus(vb, rightOperand)
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}
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||
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|
||
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// ListAppend creates a SetValueBuilder to be used in as an argument to Set().
|
||
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// The arguments can either be NameBuilders or ValueBuilders. ListAppend() only
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||
|
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// supports DynamoDB List types, so the ValueBuilder must be a List and the
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// NameBuilder must specify an item attribute of type List.
|
||
|
|
// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.UpdatingListElements
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Use ListAppend() to set item attribute "someName" to the item
|
||
|
|
// // attribute "nameOfList" with "some" and "list" appended to it
|
||
|
|
// update, err := expression.Set(expression.Name("someName"), expression.ListAppend(expression.Name("nameOfList"), expression.Value([]string{"some", "list"})))
|
||
|
|
//
|
||
|
|
// Expression Equivalent:
|
||
|
|
//
|
||
|
|
// expression.ListAppend(expression.Name("nameOfList"), expression.Value([]string{"some", "list"})
|
||
|
|
// // let :list be a ExpressionAttributeValue representing the list
|
||
|
|
// // containing "some" and "list".
|
||
|
|
// "list_append (nameOfList, :list)"
|
||
|
|
func ListAppend(leftOperand, rightOperand OperandBuilder) SetValueBuilder {
|
||
|
|
return SetValueBuilder{
|
||
|
|
leftOperand: leftOperand,
|
||
|
|
rightOperand: rightOperand,
|
||
|
|
mode: listAppendValueMode,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// ListAppend creates a SetValueBuilder to be used in as an argument to Set().
|
||
|
|
// The arguments can either be NameBuilders or ValueBuilders. ListAppend() only
|
||
|
|
// supports DynamoDB List types, so the ValueBuilder must be a List and the
|
||
|
|
// NameBuilder must specify an item attribute of type List.
|
||
|
|
// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.UpdatingListElements
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Use ListAppend() to set item attribute "someName" to the item
|
||
|
|
// // attribute "nameOfList" with "some" and "list" appended to it
|
||
|
|
// update, err := expression.Set(expression.Name("someName"), expression.Name("nameOfList").ListAppend(expression.Value([]string{"some", "list"})))
|
||
|
|
//
|
||
|
|
// Expression Equivalent:
|
||
|
|
//
|
||
|
|
// expression.Name("nameOfList").ListAppend(expression.Value([]string{"some", "list"})
|
||
|
|
// // let :list be a ExpressionAttributeValue representing the list
|
||
|
|
// // containing "some" and "list".
|
||
|
|
// "list_append (nameOfList, :list)"
|
||
|
|
func (nb NameBuilder) ListAppend(rightOperand OperandBuilder) SetValueBuilder {
|
||
|
|
return ListAppend(nb, rightOperand)
|
||
|
|
}
|
||
|
|
|
||
|
|
// ListAppend creates a SetValueBuilder to be used in as an argument to Set().
|
||
|
|
// The arguments can either be NameBuilders or ValueBuilders. ListAppend() only
|
||
|
|
// supports DynamoDB List types, so the ValueBuilder must be a List and the
|
||
|
|
// NameBuilder must specify an item attribute of type List.
|
||
|
|
// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.UpdatingListElements
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Use ListAppend() to set item attribute "someName" to a string list
|
||
|
|
// // equal to {"a", "list", "some", "list"}
|
||
|
|
// update, err := expression.Set(expression.Name("someName"), expression.Value([]string{"a", "list"}).ListAppend(expression.Value([]string{"some", "list"})))
|
||
|
|
//
|
||
|
|
// Expression Equivalent:
|
||
|
|
//
|
||
|
|
// expression.Name([]string{"a", "list"}).ListAppend(expression.Value([]string{"some", "list"})
|
||
|
|
// // let :list1 and :list2 be a ExpressionAttributeValue representing the
|
||
|
|
// // list {"a", "list"} and {"some", "list"} respectively
|
||
|
|
// "list_append (:list1, :list2)"
|
||
|
|
func (vb ValueBuilder) ListAppend(rightOperand OperandBuilder) SetValueBuilder {
|
||
|
|
return ListAppend(vb, rightOperand)
|
||
|
|
}
|
||
|
|
|
||
|
|
// IfNotExists creates a SetValueBuilder to be used in as an argument to Set().
|
||
|
|
// The first argument must be a NameBuilder representing the name where the new
|
||
|
|
// item attribute is created. The second argument can either be a NameBuilder or
|
||
|
|
// a ValueBuilder. In the case that it is a NameBuilder, the value of the item
|
||
|
|
// attribute at the name specified becomes the value of the new item attribute.
|
||
|
|
// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.PreventingAttributeOverwrites
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Use IfNotExists() to set item attribute "someName" to value 5 if
|
||
|
|
// // "someName" does not exist yet. (Prevents overwrite)
|
||
|
|
// update, err := expression.Set(expression.Name("someName"), expression.IfNotExists(expression.Name("someName"), expression.Value(5)))
|
||
|
|
//
|
||
|
|
// Expression Equivalent:
|
||
|
|
//
|
||
|
|
// expression.IfNotExists(expression.Name("someName"), expression.Value(5))
|
||
|
|
// // let :five be a ExpressionAttributeValue representing the value 5
|
||
|
|
// "if_not_exists (someName, :five)"
|
||
|
|
func IfNotExists(name NameBuilder, setValue OperandBuilder) SetValueBuilder {
|
||
|
|
return SetValueBuilder{
|
||
|
|
leftOperand: name,
|
||
|
|
rightOperand: setValue,
|
||
|
|
mode: ifNotExistsValueMode,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// IfNotExists creates a SetValueBuilder to be used in as an argument to Set().
|
||
|
|
// The first argument must be a NameBuilder representing the name where the new
|
||
|
|
// item attribute is created. The second argument can either be a NameBuilder or
|
||
|
|
// a ValueBuilder. In the case that it is a NameBuilder, the value of the item
|
||
|
|
// attribute at the name specified becomes the value of the new item attribute.
|
||
|
|
// More information: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.PreventingAttributeOverwrites
|
||
|
|
//
|
||
|
|
// Example:
|
||
|
|
//
|
||
|
|
// // Use IfNotExists() to set item attribute "someName" to value 5 if
|
||
|
|
// // "someName" does not exist yet. (Prevents overwrite)
|
||
|
|
// update, err := expression.Set(expression.Name("someName"), expression.Name("someName").IfNotExists(expression.Value(5)))
|
||
|
|
//
|
||
|
|
// Expression Equivalent:
|
||
|
|
//
|
||
|
|
// expression.Name("someName").IfNotExists(expression.Value(5))
|
||
|
|
// // let :five be a ExpressionAttributeValue representing the value 5
|
||
|
|
// "if_not_exists (someName, :five)"
|
||
|
|
func (nb NameBuilder) IfNotExists(rightOperand OperandBuilder) SetValueBuilder {
|
||
|
|
return IfNotExists(nb, rightOperand)
|
||
|
|
}
|
||
|
|
|
||
|
|
// BuildOperand creates an Operand struct which are building blocks to DynamoDB
|
||
|
|
// Expressions. Package methods and functions can establish relationships
|
||
|
|
// between operands, representing DynamoDB Expressions. The method
|
||
|
|
// BuildOperand() is called recursively when the Build() method on the type
|
||
|
|
// Builder is called. BuildOperand() should never be called externally.
|
||
|
|
// BuildOperand() aliases all strings to avoid stepping over DynamoDB's reserved
|
||
|
|
// words.
|
||
|
|
// More information on reserved words at http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html
|
||
|
|
func (nb NameBuilder) BuildOperand() (Operand, error) {
|
||
|
|
if nb.name == "" {
|
||
|
|
return Operand{}, newUnsetParameterError("BuildOperand", "NameBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
node := exprNode{
|
||
|
|
names: []string{},
|
||
|
|
}
|
||
|
|
|
||
|
|
nameSplit := strings.Split(nb.name, ".")
|
||
|
|
fmtNames := make([]string, 0, len(nameSplit))
|
||
|
|
|
||
|
|
for _, word := range nameSplit {
|
||
|
|
var substr string
|
||
|
|
if word == "" {
|
||
|
|
return Operand{}, newInvalidParameterError("BuildOperand", "NameBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
if word[len(word)-1] == ']' {
|
||
|
|
for j, char := range word {
|
||
|
|
if char == '[' {
|
||
|
|
substr = word[j:]
|
||
|
|
word = word[:j]
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if word == "" {
|
||
|
|
return Operand{}, newInvalidParameterError("BuildOperand", "NameBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Create a string with special characters that can be substituted later: $p
|
||
|
|
node.names = append(node.names, word)
|
||
|
|
fmtNames = append(fmtNames, "$n"+substr)
|
||
|
|
}
|
||
|
|
node.fmtExpr = strings.Join(fmtNames, ".")
|
||
|
|
return Operand{
|
||
|
|
exprNode: node,
|
||
|
|
}, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// BuildOperand creates an Operand struct which are building blocks to DynamoDB
|
||
|
|
// Expressions. Package methods and functions can establish relationships
|
||
|
|
// between operands, representing DynamoDB Expressions. The method
|
||
|
|
// BuildOperand() is called recursively when the Build() method on the type
|
||
|
|
// Builder is called. BuildOperand() should never be called externally.
|
||
|
|
// BuildOperand() aliases all strings to avoid stepping over DynamoDB's reserved
|
||
|
|
// words.
|
||
|
|
// More information on reserved words at http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html
|
||
|
|
func (vb ValueBuilder) BuildOperand() (Operand, error) {
|
||
|
|
expr, err := dynamodbattribute.Marshal(vb.value)
|
||
|
|
if err != nil {
|
||
|
|
return Operand{}, newInvalidParameterError("BuildOperand", "ValueBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Create a string with special characters that can be substituted later: $v
|
||
|
|
operand := Operand{
|
||
|
|
exprNode: exprNode{
|
||
|
|
values: []dynamodb.AttributeValue{*expr},
|
||
|
|
fmtExpr: "$v",
|
||
|
|
},
|
||
|
|
}
|
||
|
|
return operand, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// BuildOperand creates an Operand struct which are building blocks to DynamoDB
|
||
|
|
// Expressions. Package methods and functions can establish relationships
|
||
|
|
// between operands, representing DynamoDB Expressions. The method
|
||
|
|
// BuildOperand() is called recursively when the Build() method on the type
|
||
|
|
// Builder is called. BuildOperand() should never be called externally.
|
||
|
|
// BuildOperand() aliases all strings to avoid stepping over DynamoDB's reserved
|
||
|
|
// words.
|
||
|
|
// More information on reserved words at http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html
|
||
|
|
func (sb SizeBuilder) BuildOperand() (Operand, error) {
|
||
|
|
operand, err := sb.nameBuilder.BuildOperand()
|
||
|
|
operand.exprNode.fmtExpr = "size (" + operand.exprNode.fmtExpr + ")"
|
||
|
|
|
||
|
|
return operand, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// BuildOperand creates an Operand struct which are building blocks to DynamoDB
|
||
|
|
// Expressions. Package methods and functions can establish relationships
|
||
|
|
// between operands, representing DynamoDB Expressions. The method
|
||
|
|
// BuildOperand() is called recursively when the Build() method on the type
|
||
|
|
// Builder is called. BuildOperand() should never be called externally.
|
||
|
|
// BuildOperand() aliases all strings to avoid stepping over DynamoDB's reserved
|
||
|
|
// words.
|
||
|
|
// More information on reserved words at http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html
|
||
|
|
func (kb KeyBuilder) BuildOperand() (Operand, error) {
|
||
|
|
if kb.key == "" {
|
||
|
|
return Operand{}, newUnsetParameterError("BuildOperand", "KeyBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
ret := Operand{
|
||
|
|
exprNode: exprNode{
|
||
|
|
names: []string{kb.key},
|
||
|
|
fmtExpr: "$n",
|
||
|
|
},
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// BuildOperand creates an Operand struct which are building blocks to DynamoDB
|
||
|
|
// Expressions. Package methods and functions can establish relationships
|
||
|
|
// between operands, representing DynamoDB Expressions. The method
|
||
|
|
// BuildOperand() is called recursively when the Build() method on the type
|
||
|
|
// Builder is called. BuildOperand() should never be called externally.
|
||
|
|
// BuildOperand() aliases all strings to avoid stepping over DynamoDB's reserved
|
||
|
|
// words.
|
||
|
|
// More information on reserved words at http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html
|
||
|
|
func (svb SetValueBuilder) BuildOperand() (Operand, error) {
|
||
|
|
if svb.mode == unsetValue {
|
||
|
|
return Operand{}, newUnsetParameterError("BuildOperand", "SetValueBuilder")
|
||
|
|
}
|
||
|
|
|
||
|
|
left, err := svb.leftOperand.BuildOperand()
|
||
|
|
if err != nil {
|
||
|
|
return Operand{}, err
|
||
|
|
}
|
||
|
|
leftNode := left.exprNode
|
||
|
|
|
||
|
|
right, err := svb.rightOperand.BuildOperand()
|
||
|
|
if err != nil {
|
||
|
|
return Operand{}, err
|
||
|
|
}
|
||
|
|
rightNode := right.exprNode
|
||
|
|
|
||
|
|
node := exprNode{
|
||
|
|
children: []exprNode{leftNode, rightNode},
|
||
|
|
}
|
||
|
|
|
||
|
|
switch svb.mode {
|
||
|
|
case plusValueMode:
|
||
|
|
node.fmtExpr = "$c + $c"
|
||
|
|
case minusValueMode:
|
||
|
|
node.fmtExpr = "$c - $c"
|
||
|
|
case listAppendValueMode:
|
||
|
|
node.fmtExpr = "list_append($c, $c)"
|
||
|
|
case ifNotExistsValueMode:
|
||
|
|
node.fmtExpr = "if_not_exists($c, $c)"
|
||
|
|
default:
|
||
|
|
return Operand{}, fmt.Errorf("build operand error: unsupported mode: %v", svb.mode)
|
||
|
|
}
|
||
|
|
|
||
|
|
return Operand{
|
||
|
|
exprNode: node,
|
||
|
|
}, nil
|
||
|
|
}
|