Add WEEK ref to GVal expr reference

It helps to define the outputType of week ql reference

server/pkg/dal/runner_gval.go

@@ -94,7 +94,7 @@ var (
 			OutType: &TypeBoolean{},
 		},
 		"ge": {
-			//Handler: makeGenericCompHandler(">="),
+			// Handler: makeGenericCompHandler(">="),
 			Handler: func(args ...string) string {
 				return fmt.Sprintf("%s >= %s", args[0], args[1])
 			},
@@ -213,6 +213,12 @@ var (
 			},
 			OutType: &TypeNumber{},
 		},
+		"week": {
+			Handler: func(args ...string) string {
+				return fmt.Sprintf("week(%s)", args[0])
+			},
+			OutType: &TypeNumber{},
+		},
 		"date_format": {
 			Handler: func(args ...string) string {
 				return fmt.Sprintf("strftime(%s, %s)", args[0], args[1])

server/store/adapters/rdbms/drivers/postgres/ql.go

@@ -68,9 +68,8 @@ var (
 		},
 		"week": {
 			Handler: func(args ...exp.Expression) exp.Expression {
-				return exp.NewSQLFunctionExpression("TO_CHAR",
-					exp.NewLiteralExpression("?::TIMESTAMPTZ", args[0]),
-					exp.NewLiteralExpression("?", "IW"),
+				return exp.NewSQLFunctionExpression("EXTRACT",
+					exp.NewLiteralExpression("WEEK FROM ?", args[0]),
 				)
 			},
 		},