SQLite overhaul: custom value, query db command (#5247)

Clean up query errors

crates/nu-command/tests/commands/query/db.rs

@@ -0,0 +1,47 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+
+fn can_query_single_table() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample.db
+            | query db "select * from strings"
+            | where x =~ ell
+            | length
+        "#
+    ));
+
+    assert_eq!(actual.out, "4");
+}
+
+#[test]
+fn invalid_sql_fails() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample.db
+            | query db "select *asdfasdf"
+        "#
+    ));
+
+    assert!(actual.err.contains("syntax error"));
+}
+
+#[test]
+fn invalid_input_fails() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            "foo" | query db "select * from asdf"
+        "#
+    ));
+
+    assert!(actual.err.contains("pipeline_mismatch"));
+}
+
+#[test]
+fn scratch() {
+    assert!(true);
+}

crates/nu-command/tests/commands/query/mod.rs

@@ -0,0 +1 @@
+mod db;