Support MySQL CREATE TABLE x LIKE y statements (#663)

alecbz · web-flow · commit e05ddd3e78c5 · 2020-08-16T20:57:55.000-07:00
diff --git a/internal/endtoend/testdata/create_table_like/mysql/go/db.go b/internal/endtoend/testdata/create_table_like/mysql/go/db.go
diff --git a/internal/endtoend/testdata/create_table_like/mysql/go/models.go b/internal/endtoend/testdata/create_table_like/mysql/go/models.go
diff --git a/internal/endtoend/testdata/create_table_like/mysql/go/query.sql.go b/internal/endtoend/testdata/create_table_like/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/create_table_like/mysql/query.sql b/internal/endtoend/testdata/create_table_like/mysql/query.sql
@@ -0,0 +1,2 @@
+/* name: GetAll :many */
+SELECT * FROM super_users;
diff --git a/internal/endtoend/testdata/create_table_like/mysql/schema.sql b/internal/endtoend/testdata/create_table_like/mysql/schema.sql
@@ -0,0 +1,18 @@
+CREATE TABLE users (
+    id integer NOT NULL AUTO_INCREMENT PRIMARY KEY,
+    first_name varchar(255) NOT NULL
+);
+
+ALTER TABLE users
+    ADD COLUMN last_name varchar(255);
+
+CREATE TABLE super_users LIKE users;
+
+ALTER TABLE users
+    ADD COLUMN age integer NOT NULL;
+
+ALTER TABLE users
+    DROP COLUMN first_name;
+
+ALTER TABLE super_users
+    ADD COLUMN date_of_birth DATETIME(6);
diff --git a/internal/endtoend/testdata/create_table_like/mysql/sqlc.json b/internal/endtoend/testdata/create_table_like/mysql/sqlc.json
@@ -0,0 +1,12 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "name": "querytest",
+      "path": "go",
+      "schema": "schema.sql",
+      "queries": "query.sql",
+      "engine": "mysql:beta"
+    }
+  ]
+}
diff --git a/internal/engine/dolphin/convert.go b/internal/engine/dolphin/convert.go
@@ -111,6 +111,9 @@ func (c *cc) convertCreateTableStmt(n *pcast.CreateTableStmt) ast.Node {
 		Name:        parseTableName(n.Table),
 		IfNotExists: n.IfNotExists,
 	}
+	if n.ReferTable != nil {
+		create.ReferTable = parseTableName(n.ReferTable)
+	}
 	for _, def := range n.Cols {
 		var vals *ast.List
 		if len(def.Tp.Elems) > 0 {
diff --git a/internal/sql/ast/create_table_stmt.go b/internal/sql/ast/create_table_stmt.go
@@ -4,6 +4,7 @@ type CreateTableStmt struct {
 	IfNotExists bool
 	Name        *TableName
 	Cols        []*ColumnDef
+	ReferTable *TableName
 }
 
 func (n *CreateTableStmt) Pos() int {
diff --git a/internal/sql/catalog/table.go b/internal/sql/catalog/table.go
@@ -135,14 +135,31 @@ func (c *Catalog) createTable(stmt *ast.CreateTableStmt) error {
 	} else if err == nil {
 		return sqlerr.RelationExists(stmt.Name.Name)
 	}
+
 	tbl := Table{Rel: stmt.Name}
-	for _, col := range stmt.Cols {
-		tbl.Columns = append(tbl.Columns, &Column{
-			Name:      col.Colname,
-			Type:      *col.TypeName,
-			IsNotNull: col.IsNotNull,
-			IsArray:   col.IsArray,
-		})
+
+	if stmt.ReferTable != nil && len(stmt.Cols) != 0 {
+		return errors.New("create table node cannot have both a ReferTable and Cols")
+	}
+
+	if stmt.ReferTable != nil {
+		_, original, err := c.getTable(stmt.ReferTable)
+		if err != nil {
+			return err
+		}
+		for _, col := range original.Columns {
+			newCol := *col  // make a copy, so changes to the ReferTable don't propagate
+			tbl.Columns = append(tbl.Columns, &newCol)
+		}
+	} else {
+		for _, col := range stmt.Cols {
+			tbl.Columns = append(tbl.Columns, &Column{
+				Name:      col.Colname,
+				Type:      *col.TypeName,
+				IsNotNull: col.IsNotNull,
+				IsArray:   col.IsArray,
+			})
+		}
 	}
 	schema.Tables = append(schema.Tables, &tbl)
 	return nil

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+/* name: GetAll :many */`
	`2`	`+SELECT * FROM super_users;`
Original file line number	Diff line number	Diff line change
`@@ -4,6 +4,7 @@ type CreateTableStmt struct {`
`4`	`4`	`IfNotExists bool`
`5`	`5`	`Name *TableName`
`6`	`6`	`Cols []*ColumnDef`
	`7`	`+ ReferTable *TableName`
`7`	`8`	`}`
`8`	`9`
`9`	`10`	`func (n *CreateTableStmt) Pos() int {`