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MySQL数据库迁移SQL语句指南
一、基础迁移方法
1. 使用mysqldump进行全量迁移
-- 导出源数据库（在命令行执行）
mysqldump -u [源用户名] -p[源密码] --single-transaction --routines --triggers --events
--master-data=2 [数据库名] > migration_backup.sql-- 导入目标数据库（在命令行执行）
mysql -u [目标用户名] -p[目标密码] [目标数据库名] < migration_backup.sql
2. 只迁移表结构
-- 导出表结构
mysqldump -u [用户名] -p[密码] --no-data [数据库名] > schema_only.sql-- 导入表结构
mysql -u [用户名] -p[密码] [目标数据库] < schema_only.sql
二、大型数据库迁移策略
1. 分表迁移
-- 导出特定表
mysqldump -u [用户名] -p[密码] [数据库名] [表1] [表2] > tables_backup.sql-- 批量导出所有表（生成导出命令）
SELECT CONCAT('mysqldump -u [用户名] -p[密码] [数据库名] ', table_name, ' > ', table_name, '.sql')
FROM information_schema.tables
WHERE table_schema = '[数据库名]';
2. 分批迁移大数据表
-- 导出表中部分数据（按ID范围）
mysqldump -u [用户名] -p[密码] [数据库名] [表名] --where="id BETWEEN 1 AND 100000" > table_part1.sql-- 使用LIMIT分批导出
SELECT * FROM large_table LIMIT 0, 100000 INTO OUTFILE '/tmp/part1.csv';
三、跨版本/跨服务器迁移
1. 使用SELECT INTO OUTFILE
-- 导出数据到文件
SELECT * FROM table_name INTO OUTFILE '/tmp/table_name.csv'
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY '\n';-- 导入数据
LOAD DATA INFILE '/tmp/table_name.csv'
INTO TABLE table_name
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY '\n';
2. 使用存储过程实现增量迁移
DELIMITER //
CREATE PROCEDURE incremental_migration(IN last_id INT)
BEGINDECLARE batch_size INT DEFAULT 1000;DECLARE max_id INT;SELECT COALESCE(MAX(id), 0) INTO max_id FROM target_db.target_table;INSERT INTO target_db.target_tableSELECT * FROM source_db.source_tableWHERE id > max_id AND id <= max_id + batch_size;-- 记录迁移位置INSERT INTO migration_log (table_name, last_migrated_id, batch_size, migrate_time)VALUES ('source_table', max_id + batch_size, batch_size, NOW());
END //
DELIMITER ;
四、数据库迁移验证SQL
1. 数据一致性检查
-- 检查表记录数是否一致
SELECT (SELECT COUNT(*) FROM source_db.table1) AS source_count,(SELECT COUNT(*) FROM target_db.table1) AS target_count,(SELECT COUNT(*) FROM source_db.table1) - (SELECT COUNT(*) FROM target_db.table1) AS difference;-- 检查数据校验和
SELECT COUNT(*) AS total_rows,SUM(CRC32(CONCAT_WS(',', col1, col2, col3))) AS checksum
FROM source_db.table_name;-- 与目标库比较
SELECT (SELECT SUM(CRC32(CONCAT_WS(',', col1, col2, col3))) FROM source_db.table_name) AS source_checksum,(SELECT SUM(CRC32(CONCAT_WS(',', col1, col2, col3))) FROM target_db.table_name) AS target_checksum;
2. 索引和约束验证
-- 比较表结构
SELECT column_name, column_type, is_nullable, column_default
FROM information_schema.columns
WHERE table_schema = 'source_db' AND table_name = 'table_name'EXCEPTSELECT column_name, column_type, is_nullable, column_default
FROM information_schema.columns
WHERE table_schema = 'target_db' AND table_name = 'table_name';-- 检查索引差异
SELECT index_name, column_name, non_unique
FROM information_schema.statistics
WHERE table_schema = 'source_db' AND table_name = 'table_name'EXCEPTSELECT index_name, column_name, non_unique
FROM information_schema.statistics
WHERE table_schema = 'target_db' AND table_name = 'table_name';
五、特殊场景迁移方案
1. 迁移存储过程和函数
-- 导出所有存储过程
mysqldump -u [用户名] -p[密码] --routines --no-create-info --no-data
--no-create-db --skip-opt [数据库名] > routines.sql-- 单独导出某个存储过程
SHOW CREATE PROCEDURE procedure_name\G
2. 迁移用户和权限
-- 导出用户权限
mysql -u root -p -e "SELECT CONCAT('SHOW GRANTS FOR ''', user, '''@''', host, ''';')
FROM mysql.user WHERE user NOT IN ('root','mysql.sys')" | mysql -u root -p > all_grants.sql-- 导入用户权限
mysql -u root -p < all_grants.sql
六、自动化迁移脚本示例
#!/bin/bash
# MySQL数据库迁移脚本SOURCE_DB="source_db"
TARGET_DB="target_db"
SOURCE_USER="source_user"
SOURCE_PASS="source_pass"
TARGET_USER="target_user"
TARGET_PASS="target_pass"
BACKUP_DIR="/backup/migration"
DATE=$(date +%Y%m%d)# 创建备份目录
mkdir -p $BACKUP_DIR# 1. 导出源数据库
echo "导出源数据库..."
mysqldump -u $SOURCE_USER -p$SOURCE_PASS --single-transaction --routines --triggers --events $SOURCE_DB > $BACKUP_DIR/${SOURCE_DB}_${DATE}.sql# 2. 创建目标数据库
echo "创建目标数据库..."
mysql -u $TARGET_USER -p$TARGET_PASS -e "CREATE DATABASE IF NOT EXISTS $TARGET_DB CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci"# 3. 导入到目标数据库
echo "导入到目标数据库..."
mysql -u $TARGET_USER -p$TARGET_PASS $TARGET_DB < $BACKUP_DIR/${SOURCE_DB}_${DATE}.sql# 4. 验证迁移
echo "验证迁移结果..."
mysql -u $TARGET_USER -p$TARGET_PASS -e "SELECT COUNT(*) AS tables_migrated FROM information_schema.tables WHERE table_schema = '$TARGET_DB'"
迁移注意事项
- 版本兼容性：检查MySQL版本差异，特别是5.7到8.0的迁移
- 字符集设置：确保源和目标数据库使用相同的字符集
- 外键约束：迁移时暂时禁用外键检查
SET FOREIGN_KEY_CHECKS=0; - 大表迁移：考虑使用pt-archiver等工具分批迁移
- 停机时间：评估业务影响，尽量在低峰期执行迁移
以上SQL语句和脚本可根据实际迁移需求进行调整，建议在测试环境验证后再进行生产环境迁移。