Refer to GPT and my own idea, according to your description, you need to dynamically adjust the parameters of Mybatis call stored procedure, to adapt to the modification of stored procedure parameters. The following provides a solution based on Mybatis custom TypeHandler.
First, you need to write a custom TypeHandler that converts the parameters and types of stored procedures to the parameter types and modes of Mybatis. Here is an example TypeHandler:
public class StoredProcedureTypeHandler extends BaseTypeHandler> {
@Override
public void setNonNullParameter(PreparedStatement ps, int i, List parameter, JdbcType jdbcType) throws SQLException {
StringBuilder sb = new StringBuilder();
sb.append("{call ").append(parameter.get(0).getName()).append("(");
for (int j = 1; j < parameter.size(); j++) {
sb.append("?,");
}
sb.deleteCharAt(sb.length() - 1).append(")}");
ps.setString(i, sb.toString());
}
@Override
public List getNullableResult(ResultSet rs, String columnName) throws SQLException {
return parseStoredProcedureParams(rs.getString(columnName));
}
@Override
public List getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
return parseStoredProcedureParams(rs.getString(columnIndex));
}
@Override
public List getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
return parseStoredProcedureParams(cs.getString(columnIndex));
}
private List parseStoredProcedureParams(String paramStr) {
// 解析存储过程参数
// ...
}
}
This TypeHandler converts the name and argument list of the stored procedure into the string format required by Mybatis to call the stored procedure and sets it as the arguments of the PreparedStatement. In addition, it converts the stored procedure parameter string returned by a ResultSet into a Java object. You need to achieve parseStoredProcedureParams method according to actual situation.
Next, you need to register the TypeHandler in the Mybatis configuration file:
="com.example.StoredProcedureTypeHandler" javaType="java.util.List" jdbcType="VARCHAR"/>
In the Mapper XML file, you need to declare a select statement that returns type List to query the list of parameters for the stored procedure:
<select id="getStoredProcedureParams" resultType="java.util.List">
SELECT param_name, param_type, param_mode
FROM [sys].[sp_procedure_params_100_managed]
WHERE procedure_name = #{procedureName}
ORDER BY param_order;
select>
Finally, in Java code, you can query the list of stored procedure parameters using the selectOne method of SqlSession, which is then passed as a parameter to the Mybatis calling stored procedure method. Here is an example:
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List params = sqlSession.selectOne("com.example.MyMapper.getStoredProcedureParams", "存储过程名");
Map paramValues = new HashMap<>();
for (StoredProcedureParam param : params) {
if (param.getMode() == StoredProcedureParam.Mode.IN) {
paramValues.put(param.getName(), /* 从请求参数中获取对应的值 */);
} else {
paramValues.put(param.getName(), null);
// 输出参数需要预先设为 null，否则会抛出异常
}
}
sqlSession.selectOne("com.example.MyMapper.callStoredProcedure", new StoredProcedureCall("存储过程名", paramValues));
// 处理输出参数
for (StoredProcedureParam param : params) {
if (param.getMode() == StoredProcedureParam.Mode.OUT) {
System.out.println(param.getName() + ": " + paramValues.get(param.getName()));
}
}
} finally {
sqlSession.close();
}
Where, "Com. Example. MyMapper. GetStoredProcedureParams" and "com. Example. MyMapper. CallStoredProcedure" are two MyBatis Mapper method, Their SQL queries and calls need to be defined in the corresponding Mapper XML file. The getStoredProcedureParams method returns parameter information about the specified stored procedure, and the callStoredProcedure method invokes the specified stored procedure.
In the getStoredProcedureParams method, you can use the metadata function of the database to obtain parameter information about a specified stored procedure. For example, for an Oracle database, you can use the following SQL query:
SELECT
argument_name AS name,
data_type AS type,
IN_OUT AS mode
FROM
all_arguments
WHERE
object_name = #{procedureName}
ORDER BY
position;
This query returns the parameter information of the stored procedure, including the parameter name, parameter type, and parameter mode(input or output). You can map this information to Java objects using functions such as resultMap and resultType in MyBatis.
In the callStoredProcedure method, you can use MyBatis selectOne or update methods to execute the stored procedure call. For example, for an Oracle database, you can call a stored procedure with the following statement:
BEGIN
Name of the stored procedure(:param1, :param2,... , :paramN);
END;
where :param1, :param2,... , :paramN indicates a parameter of a stored procedure. It must correspond to the parameter name queried in the getStoredProcedureParams method. BEGIN and END are used here to encapsulate the stored procedure call, because in Oracle, stored procedure calls must be encapsulated in BEGIN and END.
After calling the stored procedure, you can take the value of the output parameter from paramValues and process it accordingly. Note that the output parameter needs to be pre-set to null, otherwise an exception will be thrown.
