type NullType byte
const (
_ NullType = iota
// IsNull the same as `is null`
IsNull
// IsNotNull the same as `is not null`
IsNotNull
)
// sql build where
func whereBuild(where map[string]interface{}) (whereSQL string, vals []interface{}, err error) {
for k, v := range where {
ks := strings.Split(k, " ")
if len(ks) > 2 {
return "", nil, fmt.Errorf("Error in query condition: %s. ", k)
}
if whereSQL != "" {
whereSQL += " AND "
}
strings.Join(ks, ",")
switch len(ks) {
case 1:
//fmt.Println(reflect.TypeOf(v))
switch v := v.(type) {
case NullType:
if v == IsNotNull {
whereSQL += fmt.Sprint(k, " IS NOT NULL")
} else {
whereSQL += fmt.Sprint(k, " IS NULL")
}
default:
whereSQL += fmt.Sprint(k, "=?")
vals = append(vals, v)
}
break
case 2:
k = ks[0]
switch ks[1] {
case "=":
whereSQL += fmt.Sprint(k, "=?")
vals = append(vals, v)
break
case ">":
whereSQL += fmt.Sprint(k, ">?")
vals = append(vals, v)
break
case ">=":
whereSQL += fmt.Sprint(k, ">=?")
vals = append(vals, v)
break
case "<":
whereSQL += fmt.Sprint(k, "<?")
vals = append(vals, v)
break
case "<=":
whereSQL += fmt.Sprint(k, "<=?")
vals = append(vals, v)
break
case "!=":
whereSQL += fmt.Sprint(k, "!=?")
vals = append(vals, v)
break
case "<>":
whereSQL += fmt.Sprint(k, "!=?")
vals = append(vals, v)
break
case "in":
whereSQL += fmt.Sprint(k, " in (?)")
vals = append(vals, v)
break
case "like":
whereSQL += fmt.Sprint(k, " like ?")
vals = append(vals, v)
}
break
}
}
return
}
使用方法:
func TestWhereBuild(t *testing.T) {
cond, vals, err := whereBuild(map[string]interface{}{
"name": "jinzhu",
"age in": []int{20, 19, 18},
})
if err != nil {
t.Fatal(err)
}
t.Log(cond)
t.Log(vals)
db.Where(cond, vals...).Find(&users)
}