Support show [full] tables from db_name

Signed-off-by: yuananf <[email protected]>

Author: yuananf

ast.go

@@ -1277,13 +1277,31 @@ func (node VindexParam) walkSubtree(visit Visit) error {
 
 // Show represents a show statement.
 type Show struct {
-	Type    string
-	OnTable TableName
-	Scope   string
+	Type          string
+	OnTable       TableName
+	ShowTablesOpt *ShowTablesOpt
+	Scope         string
 }
 
 // Format formats the node.
 func (node *Show) Format(buf *TrackedBuffer) {
+	if node.Type == "tables" && node.ShowTablesOpt != nil {
+		opt := node.ShowTablesOpt
+		if opt.DbName != "" {
+			if opt.Filter != nil {
+				buf.Myprintf("show %s%stables from %s %v", opt.Extended, opt.Full, opt.DbName, opt.Filter)
+			} else {
+				buf.Myprintf("show %s%stables from %s", opt.Extended, opt.Full, opt.DbName)
+			}
+		} else {
+			if opt.Filter != nil {
+				buf.Myprintf("show %s%stables %v", opt.Extended, opt.Full, opt.Filter)
+			} else {
+				buf.Myprintf("show %s%stables", opt.Extended, opt.Full)
+			}
+		}
+		return
+	}
 	if node.Scope == "" {
 		buf.Myprintf("show %s", node.Type)
 	} else {
@@ -1303,6 +1321,33 @@ func (node *Show) walkSubtree(visit Visit) error {
 	return nil
 }
 
+// ShowTablesOpt is show tables option
+type ShowTablesOpt struct {
+	Extended string
+	Full     string
+	DbName   string
+	Filter   *ShowFilter
+}
+
+// ShowFilter is show tables filter
+type ShowFilter struct {
+	Like   string
+	Filter Expr
+}
+
+// Format formats the node.
+func (node *ShowFilter) Format(buf *TrackedBuffer) {
+	if node.Like != "" {
+		buf.Myprintf("like '%s'", node.Like)
+	} else {
+		buf.Myprintf("where %v", node.Filter)
+	}
+}
+
+func (node *ShowFilter) walkSubtree(visit Visit) error {
+	return nil
+}
+
 // Use represents a use statement.
 type Use struct {
 	DBName TableIdent

parse_test.go

@@ -1073,7 +1073,7 @@ var (
 		output: "show processlist",
 	}, {
 		input:  "show full processlist",
-		output: "show full",
+		output: "show processlist",
 	}, {
 		input:  "show profile cpu for query 1",
 		output: "show profile",
@@ -1102,11 +1102,32 @@ var (
 		input:  "show table status",
 		output: "show table",
 	}, {
-		input:  "show tables",
-		output: "show tables",
+		input: "show tables",
+	}, {
+		input: "show tables like '%keyspace%'",
+	}, {
+		input: "show tables where 1 = 0",
+	}, {
+		input: "show tables from a",
+	}, {
+		input: "show tables from a where 1 = 0",
+	}, {
+		input: "show tables from a like '%keyspace%'",
+	}, {
+		input: "show full tables",
+	}, {
+		input: "show full tables from a",
+	}, {
+		input:  "show full tables in a",
+		output: "show full tables from a",
+	}, {
+		input: "show full tables from a like '%keyspace%'",
+	}, {
+		input: "show full tables from a where 1 = 0",
+	}, {
+		input: "show full tables like '%keyspace%'",
 	}, {
-		input:  "show full tables",
-		output: "show full",
+		input: "show full tables where 1 = 0",
 	}, {
 		input:  "show triggers",
 		output: "show triggers",