dex/vendor/github.com/go-gorp/gorp/table_bindings.go

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2015-08-25 04:08:24 +05:30
// Copyright 2012 James Cooper. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
// Package gorp provides a simple way to marshal Go structs to and from
// SQL databases. It uses the database/sql package, and should work with any
// compliant database/sql driver.
//
// Source code and project home:
// https://github.com/go-gorp/gorp
//
package gorp
import (
"bytes"
"fmt"
"reflect"
)
// CustomScanner binds a database column value to a Go type
type CustomScanner struct {
// After a row is scanned, Holder will contain the value from the database column.
// Initialize the CustomScanner with the concrete Go type you wish the database
// driver to scan the raw column into.
Holder interface{}
// Target typically holds a pointer to the target struct field to bind the Holder
// value to.
Target interface{}
// Binder is a custom function that converts the holder value to the target type
// and sets target accordingly. This function should return error if a problem
// occurs converting the holder to the target.
Binder func(holder interface{}, target interface{}) error
}
// Bind is called automatically by gorp after Scan()
func (me CustomScanner) Bind() error {
return me.Binder(me.Holder, me.Target)
}
type bindPlan struct {
query string
argFields []string
keyFields []string
versField string
autoIncrIdx int
autoIncrFieldName string
}
func (plan bindPlan) createBindInstance(elem reflect.Value, conv TypeConverter) (bindInstance, error) {
bi := bindInstance{query: plan.query, autoIncrIdx: plan.autoIncrIdx, autoIncrFieldName: plan.autoIncrFieldName, versField: plan.versField}
if plan.versField != "" {
bi.existingVersion = elem.FieldByName(plan.versField).Int()
}
var err error
for i := 0; i < len(plan.argFields); i++ {
k := plan.argFields[i]
if k == versFieldConst {
newVer := bi.existingVersion + 1
bi.args = append(bi.args, newVer)
if bi.existingVersion == 0 {
elem.FieldByName(plan.versField).SetInt(int64(newVer))
}
} else {
val := elem.FieldByName(k).Interface()
if conv != nil {
val, err = conv.ToDb(val)
if err != nil {
return bindInstance{}, err
}
}
bi.args = append(bi.args, val)
}
}
for i := 0; i < len(plan.keyFields); i++ {
k := plan.keyFields[i]
val := elem.FieldByName(k).Interface()
if conv != nil {
val, err = conv.ToDb(val)
if err != nil {
return bindInstance{}, err
}
}
bi.keys = append(bi.keys, val)
}
return bi, nil
}
type bindInstance struct {
query string
args []interface{}
keys []interface{}
existingVersion int64
versField string
autoIncrIdx int
autoIncrFieldName string
}
func (t *TableMap) bindInsert(elem reflect.Value) (bindInstance, error) {
plan := t.insertPlan
if plan.query == "" {
plan.autoIncrIdx = -1
s := bytes.Buffer{}
s2 := bytes.Buffer{}
s.WriteString(fmt.Sprintf("insert into %s (", t.dbmap.Dialect.QuotedTableForQuery(t.SchemaName, t.TableName)))
x := 0
first := true
for y := range t.Columns {
col := t.Columns[y]
if !(col.isAutoIncr && t.dbmap.Dialect.AutoIncrBindValue() == "") {
if !col.Transient {
if !first {
s.WriteString(",")
s2.WriteString(",")
}
s.WriteString(t.dbmap.Dialect.QuoteField(col.ColumnName))
if col.isAutoIncr {
s2.WriteString(t.dbmap.Dialect.AutoIncrBindValue())
plan.autoIncrIdx = y
plan.autoIncrFieldName = col.fieldName
} else {
if col.DefaultValue == "" {
s2.WriteString(t.dbmap.Dialect.BindVar(x))
if col == t.version {
plan.versField = col.fieldName
plan.argFields = append(plan.argFields, versFieldConst)
} else {
plan.argFields = append(plan.argFields, col.fieldName)
}
x++
} else {
s2.WriteString(col.DefaultValue)
}
}
first = false
}
} else {
plan.autoIncrIdx = y
plan.autoIncrFieldName = col.fieldName
}
}
s.WriteString(") values (")
s.WriteString(s2.String())
s.WriteString(")")
if plan.autoIncrIdx > -1 {
s.WriteString(t.dbmap.Dialect.AutoIncrInsertSuffix(t.Columns[plan.autoIncrIdx]))
}
s.WriteString(t.dbmap.Dialect.QuerySuffix())
plan.query = s.String()
t.insertPlan = plan
}
return plan.createBindInstance(elem, t.dbmap.TypeConverter)
}
func (t *TableMap) bindUpdate(elem reflect.Value) (bindInstance, error) {
plan := t.updatePlan
if plan.query == "" {
s := bytes.Buffer{}
s.WriteString(fmt.Sprintf("update %s set ", t.dbmap.Dialect.QuotedTableForQuery(t.SchemaName, t.TableName)))
x := 0
for y := range t.Columns {
col := t.Columns[y]
if !col.isAutoIncr && !col.Transient {
if x > 0 {
s.WriteString(", ")
}
s.WriteString(t.dbmap.Dialect.QuoteField(col.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(x))
if col == t.version {
plan.versField = col.fieldName
plan.argFields = append(plan.argFields, versFieldConst)
} else {
plan.argFields = append(plan.argFields, col.fieldName)
}
x++
}
}
s.WriteString(" where ")
for y := range t.keys {
col := t.keys[y]
if y > 0 {
s.WriteString(" and ")
}
s.WriteString(t.dbmap.Dialect.QuoteField(col.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(x))
plan.argFields = append(plan.argFields, col.fieldName)
plan.keyFields = append(plan.keyFields, col.fieldName)
x++
}
if plan.versField != "" {
s.WriteString(" and ")
s.WriteString(t.dbmap.Dialect.QuoteField(t.version.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(x))
plan.argFields = append(plan.argFields, plan.versField)
}
s.WriteString(t.dbmap.Dialect.QuerySuffix())
plan.query = s.String()
t.updatePlan = plan
}
return plan.createBindInstance(elem, t.dbmap.TypeConverter)
}
func (t *TableMap) bindDelete(elem reflect.Value) (bindInstance, error) {
plan := t.deletePlan
if plan.query == "" {
s := bytes.Buffer{}
s.WriteString(fmt.Sprintf("delete from %s", t.dbmap.Dialect.QuotedTableForQuery(t.SchemaName, t.TableName)))
for y := range t.Columns {
col := t.Columns[y]
if !col.Transient {
if col == t.version {
plan.versField = col.fieldName
}
}
}
s.WriteString(" where ")
for x := range t.keys {
k := t.keys[x]
if x > 0 {
s.WriteString(" and ")
}
s.WriteString(t.dbmap.Dialect.QuoteField(k.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(x))
plan.keyFields = append(plan.keyFields, k.fieldName)
plan.argFields = append(plan.argFields, k.fieldName)
}
if plan.versField != "" {
s.WriteString(" and ")
s.WriteString(t.dbmap.Dialect.QuoteField(t.version.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(len(plan.argFields)))
plan.argFields = append(plan.argFields, plan.versField)
}
s.WriteString(t.dbmap.Dialect.QuerySuffix())
plan.query = s.String()
t.deletePlan = plan
}
return plan.createBindInstance(elem, t.dbmap.TypeConverter)
}
func (t *TableMap) bindGet() bindPlan {
plan := t.getPlan
if plan.query == "" {
s := bytes.Buffer{}
s.WriteString("select ")
x := 0
for _, col := range t.Columns {
if !col.Transient {
if x > 0 {
s.WriteString(",")
}
s.WriteString(t.dbmap.Dialect.QuoteField(col.ColumnName))
plan.argFields = append(plan.argFields, col.fieldName)
x++
}
}
s.WriteString(" from ")
s.WriteString(t.dbmap.Dialect.QuotedTableForQuery(t.SchemaName, t.TableName))
s.WriteString(" where ")
for x := range t.keys {
col := t.keys[x]
if x > 0 {
s.WriteString(" and ")
}
s.WriteString(t.dbmap.Dialect.QuoteField(col.ColumnName))
s.WriteString("=")
s.WriteString(t.dbmap.Dialect.BindVar(x))
plan.keyFields = append(plan.keyFields, col.fieldName)
}
s.WriteString(t.dbmap.Dialect.QuerySuffix())
plan.query = s.String()
t.getPlan = plan
}
return plan
}