fix #134: Add new Num* methods in CRUD builders to count number of re…

…quired clause

createtable.go

@@ -85,6 +85,11 @@ func (ctb *CreateTableBuilder) Option(opt ...string) *CreateTableBuilder {
 	return ctb
 }
 
+// NumDefine returns the number of definitions in CREATE TABLE.
+func (ctb *CreateTableBuilder) NumDefine() int {
+	return len(ctb.defs)
+}
+
 // String returns the compiled INSERT string.
 func (ctb *CreateTableBuilder) String() string {
 	s, _ := ctb.Build()

createtable_test.go

@@ -69,3 +69,20 @@ func ExampleCreateTableBuilder_SQL() {
 	// /* before */ CREATE TEMPORARY TABLE IF NOT EXISTS demo.user /* after create */ (id BIGINT(20) NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT "user id", name VARCHAR(255) NOT NULL COMMENT "user name") /* after define */ DEFAULT CHARACTER SET utf8mb4 AS SELECT * FROM old.user WHERE name LIKE ?
 	// [%Huan%]
 }
+
+func ExampleCreateTableBuilder_NumDefine() {
+	ctb := NewCreateTableBuilder()
+	ctb.CreateTable("demo.user").IfNotExists()
+	ctb.Define("id", "BIGINT(20)", "NOT NULL", "AUTO_INCREMENT", "PRIMARY KEY", `COMMENT "user id"`)
+	ctb.Define("name", "VARCHAR(255)", "NOT NULL", `COMMENT "user name"`)
+	ctb.Define("created_at", "DATETIME", "NOT NULL", `COMMENT "user create time"`)
+	ctb.Define("modified_at", "DATETIME", "NOT NULL", `COMMENT "user modify time"`)
+	ctb.Define("KEY", "idx_name_modified_at", "name, modified_at")
+	ctb.Option("DEFAULT CHARACTER SET", "utf8mb4")
+
+	// Count the number of definitions.
+	fmt.Println(ctb.NumDefine())
+
+	// Output:
+	// 5
+}

insert.go

@@ -112,6 +112,11 @@ func (ib *InsertBuilder) Values(value ...interface{}) *InsertBuilder {
 	return ib
 }
 
+// NumValue returns the number of values to insert.
+func (ib *InsertBuilder) NumValue() int {
+	return len(ib.values)
+}
+
 // String returns the compiled INSERT string.
 func (ib *InsertBuilder) String() string {
 	s, _ := ib.Build()

insert_test.go

@@ -211,3 +211,17 @@ func ExampleInsertBuilder_subSelect_oracle() {
 	// INSERT INTO demo.user (id, name) SELECT id, name FROM demo.test WHERE id = :1
 	// [1]
 }
+
+func ExampleInsertBuilder_NumValue() {
+	ib := NewInsertBuilder()
+	ib.InsertInto("demo.user")
+	ib.Cols("id", "name")
+	ib.Values(1, "Huan Du")
+	ib.Values(2, "Charmy Liu")
+
+	// Count the number of values.
+	fmt.Println(ib.NumValue())
+
+	// Output:
+	// 2
+}

select.go

@@ -219,6 +219,11 @@ func (sb *SelectBuilder) BuilderAs(builder Builder, alias string) string {
 	return fmt.Sprintf("(%s) AS %s", sb.Var(builder), alias)
 }
 
+// NumCol returns the number of columns to select.
+func (sb *SelectBuilder) NumCol() int {
+	return len(sb.selectCols)
+}
+
 // String returns the compiled SELECT string.
 func (sb *SelectBuilder) String() string {
 	s, _ := sb.Build()

select_test.go

@@ -317,3 +317,18 @@ func ExampleSelectBuilder_customSELECT() {
 	// SELECT id, name FROM user WHERE id IN (?, ?, ?)
 	// [1 2 3]
 }
+
+func ExampleSelectBuilder_NumCol() {
+	sb := NewSelectBuilder()
+	sb.Select("id", "name", "created_at")
+	sb.From("demo.user")
+	sb.Where(
+		sb.GreaterThan("id", 1234),
+	)
+
+	// Count the number of columns.
+	fmt.Println(sb.NumCol())
+
+	// Output:
+	// 3
+}

update.go

@@ -156,6 +156,11 @@ func (ub *UpdateBuilder) Limit(limit int) *UpdateBuilder {
 	return ub
 }
 
+// NumAssignment returns the number of assignments to update.
+func (ub *UpdateBuilder) NumAssignment() int {
+	return len(ub.assignments)
+}
+
 // String returns the compiled UPDATE string.
 func (ub *UpdateBuilder) String() string {
 	s, _ := ub.Build()

update_test.go

@@ -116,3 +116,19 @@ func ExampleUpdateBuilder_SQL() {
 	// Output:
 	// /* before */ UPDATE demo.user /* after update */ SET type = ? /* after set */ ORDER BY id DESC /* after order by */ LIMIT 10 /* after limit */
 }
+
+func ExampleUpdateBuilder_NumAssignment() {
+	ub := NewUpdateBuilder()
+	ub.Update("demo.user")
+	ub.Set(
+		ub.Assign("type", "sys"),
+		ub.Incr("credit"),
+		"modified_at = UNIX_TIMESTAMP(NOW())",
+	)
+
+	// Count the number of assignments.
+	fmt.Println(ub.NumAssignment())
+
+	// Output:
+	// 3
+}