mysql存储过程中用变量做表名

DELIMITER //

CREATE PROCEDURE GetUserByYear(IN year INT)
BEGIN
    DECLARE tableName VARCHAR(255);
    SET tableName = CONCAT('user_', year);

    SET @sql = CONCAT('SELECT * FROM ', tableName, ' WHERE id = ?');
    PREPARE stmt FROM @sql;
    SET @id = 1; -- 假设我们要查询的 ID 是 1
    EXECUTE stmt USING @id;
    DEALLOCATE PREPARE stmt;
END //

DELIMITER ;

DELIMITER //

CREATE PROCEDURE GetUserByYear(IN year INT)
BEGIN
    DECLARE tableName VARCHAR(255);
    SET tableName = CONCAT('user_', year);

    IF (EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = tableName)) THEN
        SET @sql = CONCAT('SELECT * FROM ', tableName, ' WHERE id = ?');
        PREPARE stmt FROM @sql;
        SET @id = 1;
        EXECUTE stmt USING @id;
        DEALLOCATE PREPARE stmt;
    ELSE
        SELECT 'Table does not exist' AS errorMessage;
    END IF;
END //

DELIMITER ;

DELIMITER //

CREATE PROCEDURE GetUserByYear(IN year INT)
BEGIN
    DECLARE tableName VARCHAR(255);
    SET tableName = CONCAT('user_', year);

    IF (year >= 2021 AND year <= 2023) THEN
        SET @sql = CONCAT('SELECT * FROM ', tableName, ' WHERE id = ?');
        PREPARE stmt FROM @sql;
        SET @id = 1;
        EXECUTE stmt USING @id;
        DEALLOCATE PREPARE stmt;
    ELSE
        SELECT 'Invalid year' AS errorMessage;
    END IF;
END //

DELIMITER ;