package clause

// Interface clause interface
type Interface interface {
	Name() string
	Build(Builder)
	MergeClause(*Clause)
}

// ClauseBuilder clause builder, allows to customize how to build clause
type ClauseBuilder func(Clause, Builder)

type Writer interface {
	WriteByte(byte) error
	WriteString(string) (int, error)
}

// Builder builder interface
type Builder interface {
	Writer
	WriteQuoted(field interface{})

package clause_test

import (
	"reflect"
	"strings"
	"sync"
	"testing"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils/tests"
)

var db, _ = gorm.Open(tests.DummyDialector{}, nil)

func checkBuildClauses(t *testing.T, clauses []clause.Interface, result string, vars []interface{}) {
	var (
		buildNames    []string
		buildNamesMap = map[string]bool{}

		clauses := []clause.Interface{
			clause.Select{},
			clause.From{},
			clause.Where{Exprs: []clause.Expression{
				clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
				clause.Gt{Column: "age", Value: 18},
				clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}),
			}},
			clause.Where{Exprs: []clause.Expression{

		},
		{
			[]clause.Interface{clause.Select{
				Columns: []clause.Column{clause.PrimaryColumn},
			}, clause.Select{
				Columns: []clause.Column{{Name: "name"}},
			}, clause.From{}},
			"SELECT `name` FROM `users`", nil,
		},
		{
			[]clause.Interface{clause.Select{
				Expression: clause.CommaExpression{
					Exprs: []clause.Expression{
						clause.NamedExpr{"?", []interface{}{clause.Column{Name: "id"}}},

					if orCond, ok := expr.(clause.OrConditions); ok && len(orCond.Exprs) == 1 {
						where.Exprs = []clause.Expression{clause.And(where.Exprs...)}
						c.Expression = where
						stmt.Clauses["WHERE"] = c
						break
					}
				}
			}
		}

		stmt.AddClause(clause.Where{Exprs: []clause.Expression{
			clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: sd.Field.DBName}, Value: sd.ZeroValue},
		}})

											}

											exprs = append(exprs, clause.Expr{SQL: onSQL, Vars: vars})
										}
									}
								}
							}

							return clause.Join{
								Type:  joinType,
								Table: clause.Table{Name: relation.FieldSchema.Table, Alias: tableAliasName},
								ON:    clause.Where{Exprs: exprs},
							}
						}

						parentTableName := clause.CurrentTable
						for _, rel := range relations {

	switch v := value.(type) {
	case clause.OrderByColumn:
		tx.Statement.AddClause(clause.OrderBy{
			Columns: []clause.OrderByColumn{v},
		})
	case string:
		if v != "" {
			tx.Statement.AddClause(clause.OrderBy{
				Columns: []clause.OrderByColumn{{
					Column: clause.Column{Name: v, Raw: true},
				}},
			})
		}
	}
	return
}

// Limit specify the number of records to be retrieved
//

package clause

// From from clause
type From struct {
	Tables []Table
	Joins  []Join
}

// Name from clause name
func (from From) Name() string {
	return "FROM"
}

// Build build from clause
func (from From) Build(builder Builder) {
	if len(from.Tables) > 0 {
		for idx, table := range from.Tables {
			if idx > 0 {
				builder.WriteByte(',')
			}

			builder.WriteQuoted(table)
		}
	} else {

package clause

const (
	LockingStrengthUpdate    = "UPDATE"
	LockingStrengthShare     = "SHARE"
	LockingOptionsSkipLocked = "SKIP LOCKED"
	LockingOptionsNoWait     = "NOWAIT"
)

type Locking struct {
	Strength string
	Table    Table
	Options  string
}

// Name where clause name
func (locking Locking) Name() string {
	return "FOR"
}

// Build build where clause
func (locking Locking) Build(builder Builder) {

		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit0}},
			"SELECT * FROM `users` LIMIT ?",
			[]interface{}{limit0},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit0}, clause.Limit{Offset: 0}},
			"SELECT * FROM `users` LIMIT ?",
			[]interface{}{limit0},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}},