show columns from table_name targeted like select queries

go/vt/sqlparser/analyzer.go

@@ -94,8 +94,6 @@ func ASTToStatementType(stmt Statement) StatementType {
 		return StmtSRollback
 	case *Release:
 		return StmtRelease
-	case *ShowTableStatus:
-		return StmtShow
 	default:
 		return StmtUnknown
 	}

go/vt/sqlparser/ast.go

@@ -242,6 +242,7 @@ type (
 	// DDLAction is an enum for DDL.Action
 	DDLAction int8
 
+	// Load is for s3 statement
 	Load struct {
 		InfileS3 string
 	}
@@ -253,19 +254,7 @@ type (
 
 	// Show represents a show statement.
 	Show struct {
-		Extended               string
-		Type                   string
-		OnTable                TableName
-		Table                  TableName
-		ShowTablesOpt          *ShowTablesOpt
-		Scope                  Scope
-		ShowCollationFilterOpt Expr
-	}
-
-	// ShowTableStatus is a struct for SHOW TABLE STATUS queries.
-	ShowTableStatus struct {
-		DatabaseName string
-		Filter       *ShowFilter
+		Internal ShowInternal
 	}
 
 	// Use represents a use statement.
@@ -344,13 +333,47 @@ func (*Select) iSelectStatement()      {}
 func (*Union) iSelectStatement()       {}
 func (*ParenSelect) iSelectStatement() {}
 func (*Load) iStatement()              {}
-func (*ShowTableStatus) iStatement()   {}
 
 // ParenSelect can actually not be a top level statement,
 // but we have to allow it because it's a requirement
 // of SelectStatement.
 func (*ParenSelect) iStatement() {}
 
+//ShowInternal will represent all the show statement types.
+type ShowInternal interface {
+	isShowInternal()
+	SQLNode
+}
+
+//ShowLegacy is of ShowInternal type, holds the legacy show ast struct.
+type ShowLegacy struct {
+	Extended               string
+	Type                   string
+	OnTable                TableName
+	Table                  TableName
+	ShowTablesOpt          *ShowTablesOpt
+	Scope                  Scope
+	ShowCollationFilterOpt Expr
+}
+
+//ShowColumns is of ShowInternal type, holds the show columns statement.
+type ShowColumns struct {
+	Full   string
+	Table  TableName
+	DbName string
+	Filter *ShowFilter
+}
+
+// ShowTableStatus is of ShowInternal type, holds SHOW TABLE STATUS queries.
+type ShowTableStatus struct {
+	DatabaseName string
+	Filter       *ShowFilter
+}
+
+func (*ShowLegacy) isShowInternal()      {}
+func (*ShowColumns) isShowInternal()     {}
+func (*ShowTableStatus) isShowInternal() {}
+
 // InsertRows represents the rows for an INSERT statement.
 type InsertRows interface {
 	iInsertRows()
@@ -1401,6 +1424,22 @@ func (f *ForeignKeyDefinition) Format(buf *TrackedBuffer) {
 
 // Format formats the node.
 func (node *Show) Format(buf *TrackedBuffer) {
+	buf.astPrintf(node, "%v", node.Internal)
+}
+
+// Format formats the node.
+func (node *ShowColumns) Format(buf *TrackedBuffer) {
+	buf.astPrintf(node, "show %s", node.Full)
+	buf.astPrintf(node, "columns from %v", node.Table)
+
+	buf.printIf(node.DbName != "", " from "+node.DbName)
+	if node.Filter != nil {
+		buf.astPrintf(node, "%v", node.Filter)
+	}
+}
+
+// Format formats the node.
+func (node *ShowLegacy) Format(buf *TrackedBuffer) {
 	nodeType := strings.ToLower(node.Type)
 	if (nodeType == "tables" || nodeType == "columns" || nodeType == "fields" || nodeType == "index" || nodeType == "keys" || nodeType == "indexes" ||
 		nodeType == "databases" || nodeType == "keyspaces" || nodeType == "vitess_keyspaces" || nodeType == "vitess_shards" || nodeType == "vitess_tablets") && node.ShowTablesOpt != nil {

go/vt/sqlparser/ast_funcs.go

@@ -314,13 +314,13 @@ var _ ConstraintInfo = &ForeignKeyDefinition{}
 func (f *ForeignKeyDefinition) iConstraintInfo() {}
 
 // HasOnTable returns true if the show statement has an "on" clause
-func (node *Show) HasOnTable() bool {
+func (node *ShowLegacy) HasOnTable() bool {
 	return node.OnTable.Name.v != ""
 }
 
 // HasTable returns true if the show statement has a parsed table name.
 // Not all show statements parse table names.
-func (node *Show) HasTable() bool {
+func (node *ShowLegacy) HasTable() bool {
 	return node.Table.Name.v != ""
 }
 

go/vt/sqlparser/like_filter_test.go

@@ -36,7 +36,7 @@ func TestLikePrefixRegexp(t *testing.T) {
 	}
 
 	want := "^key.*$"
-	got := LikeToRegexp(show.(*Show).ShowTablesOpt.Filter.Like).String()
+	got := LikeToRegexp(show.(*Show).Internal.(*ShowLegacy).ShowTablesOpt.Filter.Like).String()
 
 	assert.Equal(t, want, got)
 }
@@ -48,7 +48,7 @@ func TestLikeAnyCharsRegexp(t *testing.T) {
 	}
 
 	want := "^.*val1.*val2.*$"
-	got := LikeToRegexp(show.(*Show).ShowTablesOpt.Filter.Like).String()
+	got := LikeToRegexp(show.(*Show).Internal.(*ShowLegacy).ShowTablesOpt.Filter.Like).String()
 
 	assert.Equal(t, want, got)
 }
@@ -60,7 +60,7 @@ func TestSingleAndMultipleCharsRegexp(t *testing.T) {
 	}
 
 	want := "^.val1.val2.*$"
-	got := LikeToRegexp(show.(*Show).ShowTablesOpt.Filter.Like).String()
+	got := LikeToRegexp(show.(*Show).Internal.(*ShowLegacy).ShowTablesOpt.Filter.Like).String()
 
 	assert.Equal(t, want, got)
 }
@@ -72,7 +72,7 @@ func TestSpecialCharactersRegexp(t *testing.T) {
 	}
 
 	want := "^\\?\\.\\*\\?$"
-	got := LikeToRegexp(show.(*Show).ShowTablesOpt.Filter.Like).String()
+	got := LikeToRegexp(show.(*Show).Internal.(*ShowLegacy).ShowTablesOpt.Filter.Like).String()
 
 	assert.Equal(t, want, got)
 }
@@ -84,7 +84,7 @@ func TestQuoteLikeSpecialCharacters(t *testing.T) {
 	}
 
 	want := "^part1.part2%part3.part4_part5.*$"
-	got := LikeToRegexp(show.(*Show).ShowTablesOpt.Filter.Like).String()
+	got := LikeToRegexp(show.(*Show).Internal.(*ShowLegacy).ShowTablesOpt.Filter.Like).String()
 
 	assert.Equal(t, want, got)
 }

go/vt/sqlparser/parse_test.go

@@ -1376,13 +1376,16 @@ var (
 	}, {
 		input: "show full tables where 1 = 0",
 	}, {
-		input: "show full columns from a like '%'",
+		input:  "show full columns in a in b like '%'",
+		output: "show full columns from a from b like '%'",
 	}, {
 		input: "show full columns from messages from test_keyspace like '%'",
 	}, {
-		input: "show full fields from a like '%'",
+		input:  "show full fields from a like '%'",
+		output: "show full columns from a like '%'",
 	}, {
-		input: "show fields from a like '%'",
+		input:  "show fields from a where 1 = 1",
+		output: "show columns from a where 1 = 1",
 	}, {
 		input:  "show triggers",
 		output: "show triggers",