sqlingo/delete.go

108 lines
2.1 KiB
Go

package sqlingo
import (
"context"
"database/sql"
"strconv"
"strings"
)
type deleteStatus struct {
scope scope
where BooleanExpression
orderBys []OrderBy
limit *int
ctx context.Context
}
type deleteWithTable interface {
Where(conditions ...BooleanExpression) deleteWithWhere
}
type deleteWithWhere interface {
toDeleteWithContext
toDeleteFinal
OrderBy(orderBys ...OrderBy) deleteWithOrder
Limit(limit int) deleteWithLimit
}
type deleteWithOrder interface {
toDeleteWithContext
toDeleteFinal
Limit(limit int) deleteWithLimit
}
type deleteWithLimit interface {
toDeleteWithContext
toDeleteFinal
}
type toDeleteWithContext interface {
WithContext(ctx context.Context) toDeleteFinal
}
type toDeleteFinal interface {
GetSQL() (string, error)
Execute() (result sql.Result, err error)
}
func (d *database) DeleteFrom(table Table) deleteWithTable {
return deleteStatus{scope: scope{Database: d, Tables: []Table{table}}}
}
func (s deleteStatus) Where(conditions ...BooleanExpression) deleteWithWhere {
s.where = And(conditions...)
return s
}
func (s deleteStatus) OrderBy(orderBys ...OrderBy) deleteWithOrder {
s.orderBys = orderBys
return s
}
func (s deleteStatus) Limit(limit int) deleteWithLimit {
s.limit = &limit
return s
}
func (s deleteStatus) GetSQL() (string, error) {
var sb strings.Builder
sb.Grow(128)
sb.WriteString("DELETE FROM ")
sb.WriteString(s.scope.Tables[0].GetSQL(s.scope))
if err := appendWhere(&sb, s.scope, s.where); err != nil {
return "", err
}
if len(s.orderBys) > 0 {
orderBySql, err := commaOrderBys(s.scope, s.orderBys)
if err != nil {
return "", err
}
sb.WriteString(" ORDER BY ")
sb.WriteString(orderBySql)
}
if s.limit != nil {
sb.WriteString(" LIMIT ")
sb.WriteString(strconv.Itoa(*s.limit))
}
return sb.String(), nil
}
func (s deleteStatus) WithContext(ctx context.Context) toDeleteFinal {
s.ctx = ctx
return s
}
func (s deleteStatus) Execute() (sql.Result, error) {
sqlString, err := s.GetSQL()
if err != nil {
return nil, err
}
return s.scope.Database.ExecuteContext(s.ctx, sqlString)
}