常用数据库validationQuery语句

validationQuery是用来验证数据库连接的查询语句，这个查询语句必须是至少返回一条数据的SELECT语句。每种数据库都有各自的验证语句，下表中收集了几种常见数据库的validationQuery。

DataBase validationQuery
hsqldb select 1 from INFORMATION_SCHEMA.SYSTEM_USERS
Oracle select 1 from dual
DB2 select 1 from sysibm.sysdummy1
MySql select 1
Microsoft SqlServer select1
postgresql select version()
ingres select 1
derby values 1
H2 select 1

配置文件

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    dynamic:
      primary: master
      datasource:
        master:
          username: test
          password: test
          url: {url}
          driver-class-name: com.cloudera.impala.jdbc41.Driver
        secondary:
          username: test
          password: test
          url: {url}
          driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
        third:
          username: test
          password: test
          url: {url}
          driver-class-name: oracle.jdbc.driver.OracleDriver
          # 注意这儿
          druid:
            filters: stat,slf4j
            initial-size: 8
            max-active: 30
            max-pool-prepared-statement-per-connection-size: 20
            max-wait: 30000
            min-evictable-idle-time-millis: 300000
            min-idle: 8
            pool-prepared-statements: true
            test-while-idle: true
            test-on-borrow: false
            test-on-return: false
            time-between-eviction-runs-millis: 60000
            validation-query: 'select 1 from dual'
            useGlobalDataSourceStat: true
            stat:
              log-slow-sql: true
              merge-sql: true
              slow-sql-millis: 10000
      druid:
        filters: stat,slf4j
        initial-size: 8
        max-active: 30
        max-pool-prepared-statement-per-connection-size: 20
        max-wait: 30000
        min-evictable-idle-time-millis: 300000
        min-idle: 8
        pool-prepared-statements: true
        test-while-idle: true
        test-on-borrow: false
        test-on-return: false
        time-between-eviction-runs-millis: 60000
        validation-query: 'select 1 '
        useGlobalDataSourceStat: true
        stat:
          log-slow-sql: true
          merge-sql: true
          slow-sql-millis: 10000