vitess.io/vitess@v0.16.2/go/vt/vtgate/semantics/typer.go (about) 1 /* 2 Copyright 2021 The Vitess Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package semantics 18 19 import ( 20 "strings" 21 22 "vitess.io/vitess/go/mysql/collations" 23 "vitess.io/vitess/go/sqltypes" 24 querypb "vitess.io/vitess/go/vt/proto/query" 25 "vitess.io/vitess/go/vt/sqlparser" 26 "vitess.io/vitess/go/vt/vtgate/engine" 27 ) 28 29 // typer is responsible for setting the type for expressions 30 // it does it's work after visiting the children (up), since the children types is often needed to type a node. 31 type typer struct { 32 exprTypes map[sqlparser.Expr]Type 33 } 34 35 // Type is the normal querypb.Type with collation 36 type Type struct { 37 Type querypb.Type 38 Collation collations.ID 39 } 40 41 func newTyper() *typer { 42 return &typer{ 43 exprTypes: map[sqlparser.Expr]Type{}, 44 } 45 } 46 47 var typeInt32 = Type{Type: sqltypes.Int32} 48 var decimal = Type{Type: sqltypes.Decimal} 49 var floatval = Type{Type: sqltypes.Float64} 50 51 func (t *typer) up(cursor *sqlparser.Cursor) error { 52 switch node := cursor.Node().(type) { 53 case *sqlparser.Literal: 54 switch node.Type { 55 case sqlparser.IntVal: 56 t.exprTypes[node] = typeInt32 57 case sqlparser.StrVal: 58 t.exprTypes[node] = Type{Type: sqltypes.VarChar} // TODO - add system default collation name 59 case sqlparser.DecimalVal: 60 t.exprTypes[node] = decimal 61 case sqlparser.FloatVal: 62 t.exprTypes[node] = floatval 63 } 64 case sqlparser.AggrFunc: 65 code, ok := engine.SupportedAggregates[strings.ToLower(node.AggrName())] 66 if ok { 67 typ, ok := engine.OpcodeType[code] 68 if ok { 69 t.exprTypes[node] = Type{Type: typ} 70 } 71 } 72 } 73 return nil 74 } 75 76 func (t *typer) setTypeFor(node *sqlparser.ColName, typ Type) { 77 t.exprTypes[node] = typ 78 }