mysql 存储过程读写文件

DELIMITER //

CREATE PROCEDURE ExportToCSV(IN tableName VARCHAR(255), IN filePath VARCHAR(255))
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE colName VARCHAR(255);
    DECLARE colValue VARCHAR(255);
    DECLARE cur CURSOR FOR SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = tableName;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    -- 写入文件头
    SET @sql = CONCAT('SELECT CONCAT(\',\', column_name) INTO OUTFILE \'', filePath, '\' FROM ', tableName, ' LIMIT 1');
    PREPARE stmt FROM @sql;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;

    -- 写入数据行
    read_loop: LOOP
        FETCH cur INTO colName;
        IF done THEN
            LEAVE read_loop;
        END IF;

        SET @sql = CONCAT('SELECT CONCAT(\',\', ', colName, ') INTO OUTFILE \'', filePath, '\' APPEND FROM ', tableName);
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;