a tool of sql builder, build sql for sql.DB, sqlx, gorp, or build condition sql for some orm framework, like gorm....
Builder: build sql like: SELECT * FROM t_foo WHERE name Like "%xx%" ORDER BY ID DESC
BuilderX: build sql like: SELECT DISTINCT(f.id) AS `f.id` FROM t_foo f INNER JOIN t_bar b ON ....
c := Cat{}
builder := NewBuilder(&c)
builder.Gte("id", 10000)
builder.And(SubCondition().Gte("price", catRo.Price).OR().Eq("is_sold", catRo.IsSold))
....
builderX := NewBuilderX(nil,"") //or, NewBuilderX(&cat,"c")
builderX.ResultKeys( "c.color","p.id","COUNT(DISTINCT c.id) AS `c.id_count`")
....
import (
. "github.com/x-ream/sqlxb"
)
type Cat struct {
Id uint64 `db:"id"`
Name string `db:"name"`
Age uint `db:"age"`
Color string `db:"color"`
Weight float64 `db:"weight"`
IsSold *bool `db:"is_sold"`
Price *float64 `db:"price"`
CreateAt time.Time `db:"create_at"`
}
func (*Cat) TableName() string {
return "t_cat"
}
// IsSold, Price, fields can be zero, must be pointer, like Java Boolean....
// sqlxb has func: Bool(true), Int(v) ....
// sqlxb no relect, not support omitempty, should rewrite ro, dto
type CatRo struct {
Name string `json:"name, string"`
IsSold *bool `json:"isSold, *bool"`
Price *float64 `json:"price, *float64"`
Age uint `json:"age", unit`
}
func main() {
cat := Cat{
Id: 100002,
Name: "Tuanzi",
Age: 1,
Color: "B",
Weight: 8.5,
IsSold: Bool(true),
Price: Float64(10000.00),
CreateAt: time.Now(),
}
// INSERT .....
// PREPARE TO QUERY
catRo := CatRo{
Name: "Tu",
IsSold: nil,
Price: Float64(5000.00),
Age: 1,
}
preCondition := func() bool {
if cat.Color == "W" {
return true
} else if cat.Weight <= 3 {
return false
} else {
return true
}
}
c := Cat{}
var builder = NewBuilder(&c)
builder.LikeRight("name",catRo.Name)
builder.X("weight <> ?", 0) //X(k, v...), hardcode func, value 0 and nil will NOT ignore
//Eq,Ne,Gt.... value 0 and nil will ignore, like as follow: OR().Eq("is_sold", catRo.IsSold)
builder.And(SubCondition().Gte("price", catRo.Price).OR().Gte("age", catRo.Age).OR().Eq("is_sold", catRo.IsSold))
//func Bool NOT designed for value nil or 0; designed to convert complex logic to bool
//Decorator pattern suggest to use func Bool preCondition, like:
//myBoolDecorator := NewMyBoolDecorator(para)
//builder.Bool(myBoolDecorator.fooCondition, func(cb *ConditionBuilder) {
builder.Bool(preCondition, func(cb *ConditionBuilder) {
cb.Or(SubCondition().Lt("price", 5000))
})
builder.Sort("id", ASC)
builder.Paged().Rows(10).Last(100)
vs, dataSql, countSql, _ := builder.Build().Sql()
// ....
//dataSql: SELECT * FROM t_cat WHERE id > ? AND name LIKE ? AND weight <> 0 AND (price >= ? OR age >= ?) OR (price < ?)
//ORDER BY id ASC LIMIT 10
//countSql: SELECT COUNT(*) FROM t_cat WHERE name LIKE ? AND weight <> 0 AND (price >= ? OR age >= ?) OR (price < ?)
//sqlx: err = Db.Select(&catList, dataSql,vs...)
_, conditionSql := builder.Build().SqlOfCondition()
//conditionSql: id > ? AND name LIKE ? AND weight <> 0 AND (price >= ? OR age >= ?) OR (price < ?)
}