推荐一个 MYSQL 的命令行的客户端 MYCLI

MYCLI 是一个 MySQL 命令行客户端工具 , 可以实现自动补全（auto-completion）和语法高亮，平时测试环境维护一些数据还是蛮方便的。

https://github.com/dbcli/mycli ；对应 postgres 也有相应的 pgcli https://github.com/dbcli/pgcli 。

#记录 MYSQL 的慢查询

默认 /etc/my.cnf mysql

在[mysqld]下加入

log-error=/usr/local/mysql/log/error.log #错误日志
log=/usr/local/mysql/log/mysql.log #查询日志
log-slow-queries= /usr/local/mysql/log/slowquery.log #慢查询日志

什么是慢查询？

执行特别慢的sql会查到这个日志文件里。至于什么叫比较慢，由你自己来定义。譬如你认为是1秒就算慢了，那么要加入

log-slow-queries = /usr/local/mysql/var/slowquery.log #这个是上面的
long_query_time = 1 #一秒，代表你认为1秒就算慢了，当然你可以改成比1小的数字

log-queries-not-using-indexes #如果执行的SQL语句没有使用索引，则mysql数据库同样会将这条SQL语句记录到慢查询日志文件中

Java, JDBC and MySQL Types

Table 5.2 MySQL Types to Java Types for ResultSet.getObject()

MySQL Type Name	Return value of `GetColumnClassName`	Returned as Java Class
`BIT(1)` (new in MySQL-5.0)	`BIT`	`java.lang.Boolean`
`BIT( > 1)` (new in MySQL-5.0)	`BIT`	`byte[]`
`TINYINT`	`TINYINT`	`java.lang.Boolean` if the configuration property `tinyInt1isBit` is set to`true` (the default) and the storage size is 1, or `java.lang.Integer` if not.
`BOOL`, `BOOLEAN`	`TINYINT`	See `TINYINT`, above as these are aliases for `TINYINT(1)`, currently.
`SMALLINT[(M)] [UNSIGNED]`	`SMALLINT [UNSIGNED]`	`java.lang.Integer` (regardless of whether it is `UNSIGNED` or not)
`MEDIUMINT[(M)] [UNSIGNED]`	`MEDIUMINT [UNSIGNED]`	`java.lang.Integer` (regardless of whether it is `UNSIGNED` or not)
`INT,INTEGER[(M)] [UNSIGNED]`	`INTEGER [UNSIGNED]`	`java.lang.Integer`, if `UNSIGNED` `java.lang.Long`
`BIGINT[(M)] [UNSIGNED]`	`BIGINT [UNSIGNED]`	`java.lang.Long`, if UNSIGNED `java.math.BigInteger`
`FLOAT[(M,D)]`	`FLOAT`	`java.lang.Float`
`DOUBLE[(M,B)]`	`DOUBLE`	`java.lang.Double`
`DECIMAL[(M[,D])]`	`DECIMAL`	`java.math.BigDecimal`
`DATE`	`DATE`	`java.sql.Date`
`DATETIME`	`DATETIME`	`java.sql.Timestamp`
`TIMESTAMP[(M)]`	`TIMESTAMP`	`java.sql.Timestamp`
`TIME`	`TIME`	`java.sql.Time`
`YEAR[(2\|4)]`	`YEAR`	If `yearIsDateType` configuration property is set to `false`, then the returned object type is `java.sql.Short`. If set to `true` (the default), then the returned object is of type `java.sql.Date` with the date set to January 1st, at midnight.
`CHAR(M)`	`CHAR`	`java.lang.String` (unless the character set for the column is `BINARY`, then`byte[]` is returned.
`VARCHAR(M) [BINARY]`	`VARCHAR`	`java.lang.String` (unless the character set for the column is `BINARY`, then`byte[]` is returned.
`BINARY(M)`	`BINARY`	`byte[]`
`VARBINARY(M)`	`VARBINARY`	`byte[]`
`TINYBLOB`	`TINYBLOB`	`byte[]`
`TINYTEXT`	`VARCHAR`	`java.lang.String`
`BLOB`	`BLOB`	`byte[]`
`TEXT`	`VARCHAR`	`java.lang.String`
`MEDIUMBLOB`	`MEDIUMBLOB`	`byte[]`
`MEDIUMTEXT`	`VARCHAR`	`java.lang.String`
`LONGBLOB`	`LONGBLOB`	`byte[]`
`LONGTEXT`	`VARCHAR`	`java.lang.String`
`ENUM('value1','value2',...)`	`CHAR`	`java.lang.String`
`SET('value1','value2',...)`	`CHAR`	`java.lang.String`