fix: table query field is null

@@ -124,6 +124,19 @@ func (t SQLType) ToString() string {
 	return string(t)
 }
 
+func (t SQLType) IsString() bool {
+	if t == String {
+		return true
+	}
+	if t == Date {
+		return true
+	}
+	if t == Datetime {
+		return true
+	}
+	return false
+}
+
 func EnumsDescription(m map[string]string, key string) string {
 	if v, ok := m[key]; ok {
 		return v

@@ -91,14 +91,14 @@ type Condition struct {
 
 func (c Condition) SetWhere(q *gorm.DB) {
 	if len(c.Like) > 0 {
-		q.Where(fmt.Sprintf("%v like '%%%v%%'", c.Field.SQLName, c.Like))
+		q.Where(fmt.Sprintf("%v like '%%%v%%'", FormatIfNull(c.Field), c.Like))
 	}
 	if len(c.In) > 0 {
-		q.Where(fmt.Sprintf("%v in %v", c.Field.SQLName, c.InArgs(c.In)))
+		q.Where(fmt.Sprintf("%v in %v", FormatIfNull(c.Field), c.InArgs(c.In)))
 	}
 	if len(c.Ex) > 0 {
 		in := c.InArgs(c.Ex)
-		q.Where(fmt.Sprintf("%v not in %v", c.Field.SQLName, in))
+		q.Where(fmt.Sprintf("%v not in %v", FormatIfNull(c.Field), in))
 	}
 	if len(c.Range) > 0 {
 		for _, item := range c.Range {
@@ -115,7 +115,7 @@ func (c Condition) SetWhere(q *gorm.DB) {
 				continue
 			}
 			q.Where(fmt.Sprintf("%s %s %s",
-				c.Field.SQLName,
+				FormatIfNull(c.Field),
 				opVal,
 				c.formatByOp(item.Op, val),
 			))
@@ -129,6 +129,13 @@ func (c Condition) SetWhere(q *gorm.DB) {
 	}
 }
 
+func FormatIfNull(f *domain.Field) string {
+	if domain.SQLType(f.SQLType).IsString() {
+		return fmt.Sprintf("ifnull(%s,'')", f.SQLName)
+	}
+	return f.SQLName
+}
+
 var opMap = map[string]string{
 	"=":        "=",
 	">":        ">",