81 lines
2.1 KiB
Go
81 lines
2.1 KiB
Go
// Copyright 2013 The ql Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSES/QL-LICENSE file.
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// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package stmts
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import (
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"github.com/pingcap/tidb/context"
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"github.com/pingcap/tidb/plan/plans"
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"github.com/pingcap/tidb/rset"
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"github.com/pingcap/tidb/rset/rsets"
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"github.com/pingcap/tidb/stmt"
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"github.com/pingcap/tidb/util/format"
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)
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var _ stmt.Statement = (*ExplainStmt)(nil)
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// ExplainStmt is a statement to provide information about how is SQL statement executed
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// or get columns information in a table.
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// See: https://dev.mysql.com/doc/refman/5.7/en/explain.html
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type ExplainStmt struct {
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S stmt.Statement
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Text string
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}
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// Explain implements the stmt.Statement Explain interface.
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func (s *ExplainStmt) Explain(ctx context.Context, w format.Formatter) {
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if x, ok := s.S.(*ShowStmt); ok {
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x.SetText(s.Text)
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x.Explain(ctx, w)
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return
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}
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for {
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x, ok := s.S.(*ExplainStmt)
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if !ok {
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s.S.Explain(ctx, w)
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return
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}
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s = x
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}
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}
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// IsDDL implements the stmt.Statement IsDDL interface.
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func (s *ExplainStmt) IsDDL() bool {
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return false
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}
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// OriginText implements the stmt.Statement OriginText interface.
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func (s *ExplainStmt) OriginText() string {
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return s.Text
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}
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// SetText implements the stmt.Statement SetText interface.
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func (s *ExplainStmt) SetText(text string) {
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s.Text = text
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}
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// Exec implements the stmt.Statement Exec interface.
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func (s *ExplainStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
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if v, ok := s.S.(*ShowStmt); ok {
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return v.Exec(ctx)
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}
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return rsets.Recordset{Ctx: ctx, Plan: &plans.ExplainDefaultPlan{S: s.S}}, nil
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}
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