Merge pull request #250 from dolthub/james/lateral

support `LATERAL` syntax

go/vt/sqlparser/ast.go

@@ -4050,6 +4050,7 @@ type AliasedTableExpr struct {
 	As         TableIdent
 	Hints      *IndexHints
 	AsOf       *AsOf
+	Lateral    bool
 }
 
 type AsOf struct {
@@ -4069,18 +4070,24 @@ func (node *AsOf) walkSubtree(visit Visit) error {
 
 // Format formats the node.
 func (node *AliasedTableExpr) Format(buf *TrackedBuffer) {
+	if node.Lateral {
+		buf.Myprintf("%s ", keywordStrings[LATERAL])
+	}
+
 	switch node.Expr.(type) {
 	case *ValuesStatement:
 		buf.Myprintf("(%v)", node.Expr)
 	default:
 		buf.Myprintf("%v%v", node.Expr, node.Partitions)
 	}
+
 	if node.AsOf != nil {
 		buf.Myprintf(" %v", node.AsOf)
 	}
 	if !node.As.IsEmpty() {
 		buf.Myprintf(" as %v", node.As)
 	}
+
 	switch node := node.Expr.(type) {
 	case *ValuesStatement:
 		if len(node.Columns) > 0 {
@@ -4091,6 +4098,7 @@ func (node *AliasedTableExpr) Format(buf *TrackedBuffer) {
 			buf.Myprintf(" %v", node.Columns)
 		}
 	}
+
 	if node.Hints != nil {
 		// Hint node provides the space padding.
 		buf.Myprintf("%v", node.Hints)

go/vt/sqlparser/parse_test.go

@@ -311,13 +311,33 @@ var (
 			input: "select a from (select 1 as a from tbl1 union select 2 from tbl2) as t",
 		}, {
 			input: "select a from (select 1 as a from tbl1 union select 2 from tbl2) as t (a, b)",
-		}, {
+		},
+		{
 			input: "select a from (values row(1, 2), row('a', 'b')) as t (a, b)",
-		}, {
+		},
+		{
 			input: "select a from (values row(1, 2), row('a', 'b')) as t1 join (values row(3, 4), row('c', 'd')) as t2",
-		}, {
+		},
+		{
 			input: "select a from (values row(1, 2), row('a', 'b')) as t1 (w, x) join (values row(3, 4), row('c', 'd')) as t2 (y, z)",
-		}, {
+		},
+		{
+			input: "select a from (values row(1, 2), row('a', 'b')) as t1 (w, x) join lateral (values row(3, 4), row('c', 'd')) as t2 (y, z)",
+		},
+		{
+			input: "select a from t1, lateral (select b from t2) as sq",
+		},
+		{
+			input: "select a from t1 join lateral (select b from t2) as sq",
+		},
+		{
+			input: "select a from t1 natural join lateral (select b from t2) as sq",
+		},
+		{
+			input: "select a from t1 join lateral (select b from t2) sq",
+			output: "select a from t1 join lateral (select b from t2) as sq",
+		},
+		{
 			// TODO: These forms are not yet supported due to a grammar conflict
 			// 	input: "values row(1, 2), row('a', 'b')",
 			// }, {
@@ -1083,10 +1103,12 @@ var (
 		}, {
 			input: "delete a, b from a, b where a.id = b.id and b.name = 'test'",
 			output: "delete a, b from a, b where a.id = b.id and b.`name` = 'test'",
-		}, {
+		},
+		{
 			input:  "delete from a1, a2 using t1 as a1 inner join t2 as a2 where a1.id=a2.id",
 			output: "delete a1, a2 from t1 as a1 join t2 as a2 where a1.id = a2.id",
-		}, {
+		},
+		{
 			input: "savepoint abc",
 		}, {
 			input:  "savepoint `ab_cd`",
@@ -4074,6 +4096,14 @@ func TestInvalid(t *testing.T) {
 			"name 'name'",
 		err: "multiple definitions of attribute name",
 	},
+	{
+		input: "select * from t join lateral t2",
+		err:   "syntax error",
+	},
+	{
+		input: "select * from t join lateral (select * from t2)",
+		err:   "Every derived table must have its own alias",
+	},
 	}
 
 	for _, tcase := range invalidSQL {