-- Concatenation refers to the operation of joining two or more strings together into a single string. -- This is commonly used to combine data from different columns or to format strings for output. ...

To provide native support for JSON data types within the SQL environment, PostgreSQL implements the SQL/JSON data model. This model comprises sequences of items. Each item can hold SQL scalar values, ...

其他数据库没有提供数组类型，但是可以使用其他方法实现，以下是 MySQL 中的实现： WITH RECURSIVE paths (start_station, stop_station, stops, path) AS ( SELECT station_name, next_station, 1, CAST(CONCAT(station_name , ',', next_station) AS ...

AND username LIKE CONCAT('%', #{username}, '%') </when> <when test="sex ... 如果你的数据库支持自动增长主键（如MySQL的AUTO_INCREMENT），推荐使用这种方式。如果不支持，可以使用<selectKey>标签手动获取生成的主键值。 <trim>标签可以看作是<where>和<set>标签的通用版，它允许我们 ...

The function xmlconcat concatenates a list of individual XML values to create a single value containing an XML content fragment. Null values are omitted; the result is only null if there are no ...