sqlparser: Support new SQL functions

sqlparser/CHANGELOG.md

@@ -3,6 +3,7 @@
 - Treat the result of `sum()` as nullable when inferring types.
 - Support features added in sqlite 3.44:
   - `ORDER BY` clauses as part of aggregate functions.
+  - Support `concat`, `concat_ws` and `string_agg`.
 
 ## 0.32.0
 

sqlparser/lib/src/analysis/steps/linting_visitor.dart

@@ -278,6 +278,7 @@ class LintingVisitor extends RecursiveVisitor<void, void> {
       'format' || 'unixepoch' => SqliteVersion.v3_38,
       'unhex' => SqliteVersion.v3_41,
       'timediff' || 'octet_length' => SqliteVersion.v3_43,
+      'concat' || 'concat_ws' || 'string_agg' => SqliteVersion.v3_44,
       _ => null,
     };
 

sqlparser/lib/src/analysis/types/resolving_visitor.dart

@@ -573,7 +573,16 @@ class TypeResolver extends RecursiveVisitor<TypeExpectation, void> {
       case 'upper':
         nullableIfChildIs();
         return _textType.withoutNullabilityInfo;
+      case 'concat':
+        return _textType;
+      case 'concat_ws':
+        // null if the first argument is null
+        if (params.isNotEmpty) {
+          session._addRelation(NullableIfSomeOtherIs(e, [params.first]));
+        }
+        return _textType.withoutNullabilityInfo;
       case 'group_concat':
+      case 'string_agg':
         return _textType.withNullable(true);
       case 'date':
       case 'time':

sqlparser/test/analysis/types2/misc_cases_test.dart

@@ -66,6 +66,12 @@ const Map<String, ResolvedType?> _types = {
   "SELECT unhex('ab') = ?": ResolvedType(type: BasicType.blob, nullable: true),
   'SELECT unhex(?)': ResolvedType(type: BasicType.text),
   'SELECT 1 GROUP BY 1 HAVING ? ': ResolvedType.bool(),
+  "SELECT concat(1, NULL, 2) = ?":
+      ResolvedType(type: BasicType.text, nullable: false),
+  "SELECT concat_ws(',', 1, 2) = ?":
+      ResolvedType(type: BasicType.text, nullable: false),
+  "SELECT concat_ws(NULL, 1, 2) = ?":
+      ResolvedType(type: BasicType.text, nullable: true),
 };
 
 SqlEngine _spawnEngine() {