Files
nushell/crates/nu-command/src/stor/delete.rs
2023-12-13 16:24:16 +01:00

141 lines
4.7 KiB
Rust

use crate::database::{SQLiteDatabase, MEMORY_DB};
use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
Type, Value,
};
#[derive(Clone)]
pub struct StorDelete;
impl Command for StorDelete {
fn name(&self) -> &str {
"stor delete"
}
fn signature(&self) -> Signature {
Signature::build("stor delete")
.input_output_types(vec![(Type::Nothing, Type::Table(vec![]))])
.required_named(
"table-name",
SyntaxShape::String,
"name of the table you want to insert into",
Some('t'),
)
.named(
"where-clause",
SyntaxShape::String,
"a sql string to use as a where clause without the WHERE keyword",
Some('w'),
)
.allow_variants_without_examples(true)
.category(Category::Database)
}
fn usage(&self) -> &str {
"Delete a table or specified rows in the in-memory sqlite database."
}
fn search_terms(&self) -> Vec<&str> {
vec!["sqlite", "remove", "table", "saving", "drop"]
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Delete a table from the in-memory sqlite database",
example: "stor delete --table-name nudb",
result: None,
},
Example {
description:
"Delete some rows from the in-memory sqlite database with a where clause",
example: "stor delete --table-name nudb --where-clause \"int1 == 5\"",
result: None,
},
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
_input: PipelineData,
) -> Result<PipelineData, ShellError> {
let span = call.head;
// For dropping/deleting an entire table
let table_name_opt: Option<String> = call.get_flag(engine_state, stack, "table-name")?;
// For deleting rows from a table
let where_clause_opt: Option<String> =
call.get_flag(engine_state, stack, "where-clause")?;
if table_name_opt.is_none() && where_clause_opt.is_none() {
return Err(ShellError::MissingParameter {
param_name: "requires at least one of table-name or where-clause".into(),
span,
});
}
if table_name_opt.is_none() && where_clause_opt.is_some() {
return Err(ShellError::MissingParameter {
param_name: "using the where-clause requires the use of a table-name".into(),
span,
});
}
// Open the in-mem database
let db = Box::new(SQLiteDatabase::new(std::path::Path::new(MEMORY_DB), None));
if let Some(new_table_name) = table_name_opt {
let where_clause = match where_clause_opt {
Some(where_stmt) => where_stmt,
None => String::new(),
};
if let Ok(conn) = db.open_connection() {
let sql_stmt = if where_clause.is_empty() {
// We're deleting an entire table
format!("DROP TABLE {}", new_table_name)
} else {
// We're just deleting some rows
let mut delete_stmt = format!("DELETE FROM {} ", new_table_name);
// Yup, this is a bit janky, but I'm not sure a better way to do this without having
// --and and --or flags as well as supporting ==, !=, <>, is null, is not null, etc.
// and other sql syntax. So, for now, just type a sql where clause as a string.
delete_stmt.push_str(&format!("WHERE {}", where_clause));
delete_stmt
};
// dbg!(&sql_stmt);
conn.execute(&sql_stmt, [])
.map_err(|err| ShellError::GenericError {
error: "Failed to open SQLite connection in memory from delete".into(),
msg: err.to_string(),
span: Some(Span::test_data()),
help: None,
inner: vec![],
})?;
}
}
// dbg!(db.clone());
Ok(Value::custom_value(db, span).into_pipeline_data())
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(StorDelete {})
}
}