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Pre: simplify values SQL expansion.

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This uses `interpose` instead of manual looping.
This commit is contained in:
Richard Newman 2017-06-02 13:34:02 -07:00 committed by Richard Newman
parent 63574af7ac
commit 70c5bcfa99
1 changed files with 16 additions and 18 deletions
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34
query-sql/src/lib.rs
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@ -434,16 +434,13 @@ impl QueryFragment for Values {
//
// We don't want to use an undocumented SQLite quirk, and we're a little concerned that some
// SQL systems will not optimize WITH statements well. It's also convenient to have an in
// place table to query, so for now we implement option 3).
// place table to query, so for now we implement option 3.
if let &Values::Named(ref names, _) = self {
let alias = &names[0];
out.push_sql("SELECT 0 AS ");
out.push_identifier(alias.as_str())?;
for alias in &names[1..] {
out.push_sql(", 0 AS ");
out.push_identifier(alias.as_str())?;
}
out.push_sql("SELECT ");
interpose!(alias, names,
{ out.push_sql("0 AS ");
out.push_identifier(alias.as_str())? },
{ out.push_sql(", ") });
out.push_sql(" WHERE 0 UNION ALL ");
}
@ -626,30 +623,31 @@ mod tests {
#[test]
fn test_unnamed_values() {
let build = |values| build(&Values::Unnamed(values));
assert_eq!(build(vec![vec![TypedValue::Long(1)]]),
let build = |len, values| build(&Values::Unnamed(len, values));
assert_eq!(build(1, vec![TypedValue::Long(1)]),
"VALUES (1)");
assert_eq!(build(vec![vec![TypedValue::Boolean(false), TypedValue::Long(1)]]),
assert_eq!(build(2, vec![TypedValue::Boolean(false), TypedValue::Long(1)]),
"VALUES (0, 1)");
assert_eq!(build(vec![vec![TypedValue::Boolean(false), TypedValue::Long(1)],
vec![TypedValue::Boolean(true), TypedValue::Long(2)]]),
assert_eq!(build(2, vec![TypedValue::Boolean(false), TypedValue::Long(1),
TypedValue::Boolean(true), TypedValue::Long(2)]),
"VALUES (0, 1), (1, 2)");
}
#[test]
fn test_named_values() {
let build = |names: Vec<_>, values| build(&Values::Named(names.into_iter().map(Variable::from_valid_name).collect(), values));
assert_eq!(build(vec!["?a"], vec![vec![TypedValue::Long(1)]]),
assert_eq!(build(vec!["?a"], vec![TypedValue::Long(1)]),
"SELECT 0 AS `?a` WHERE 0 UNION ALL VALUES (1)");
assert_eq!(build(vec!["?a", "?b"], vec![vec![TypedValue::Boolean(false), TypedValue::Long(1)]]),
assert_eq!(build(vec!["?a", "?b"], vec![TypedValue::Boolean(false), TypedValue::Long(1)]),
"SELECT 0 AS `?a`, 0 AS `?b` WHERE 0 UNION ALL VALUES (0, 1)");
assert_eq!(build(vec!["?a", "?b"],
vec![vec![TypedValue::Boolean(false), TypedValue::Long(1)],
vec![TypedValue::Boolean(true), TypedValue::Long(2)]]),
vec![TypedValue::Boolean(false), TypedValue::Long(1),
TypedValue::Boolean(true), TypedValue::Long(2)]),
"SELECT 0 AS `?a`, 0 AS `?b` WHERE 0 UNION ALL VALUES (0, 1), (1, 2)");
}