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47 lines
1.2 KiB
47 lines
1.2 KiB
// Copyright 2020 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 parser
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import (
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"github.com/pingcap/parser/ast"
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)
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// GetDefaultDB checks if all columns in the AST have explicit DBName. If not, return specified DBName.
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func GetDefaultDB(sel ast.StmtNode, dbName string) string {
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implicitDB := &implicitDatabase{}
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sel.Accept(implicitDB)
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if implicitDB.hasImplicit {
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return dbName
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}
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return ""
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}
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type implicitDatabase struct {
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hasImplicit bool
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}
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func (i *implicitDatabase) Enter(in ast.Node) (out ast.Node, skipChildren bool) {
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switch x := in.(type) {
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case *ast.TableName:
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if x.Schema.L == "" {
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i.hasImplicit = true
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}
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return in, true
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}
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return in, i.hasImplicit
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}
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func (i *implicitDatabase) Leave(in ast.Node) (out ast.Node, ok bool) {
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return in, true
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}
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