Detailed description of MyBatis reverse engineering and mybatis Reverse Engineering

Detailed description of MyBatis reverse engineering and mybatis Reverse Engineering

1. What is mybatis reverse engineering?

When using mybatis, programmers need to write their own SQL statements. The number of SQL statements for a single table is large. mybatis provides a tool to generate mybatis code execution based on the database table, this tool is a reverse engineering.
Reverse Engineering: generates code (mapper. xml, mapper. java, and pojo) for a single database table ..)

Mybatis-generator-core-1.3.2.jar-jar core package required for reverse engineering operation

2. Configure the configuration file of the Reverse Engineering

Configuration File generatorConfig. xml

<? Xml version = "1.0" encoding = "UTF-8"?> <! DOCTYPE generatorConfiguration PUBLIC "-// mybatis.org//DTD MyBatis Generator Configuration 1.0 //" http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd "> <generatorConfiguration> <context id =" testTables "targetRuntime =" MyBatis3 "> <commentGenerator> <! -- Whether to remove automatically generated comments true: Yes: false: No --> <property name = "suppressAllComments" value = "true"/> </commentGenerator> <! -- Database connection information: Driver Class, connection address, user name, password --> <jdbcConnection driverClass = "com. mysql. jdbc. driver "connectionURL =" jdbc: mysql: // localhost: 3306/mybatis "userId =" root "password =" 123 "> </jdbcConnection> <! -- <JdbcConnection driverClass = "oracle. jdbc. oracleDriver "connectionURL =" jdbc: oracle: thin: @ 127.0.0.1: 1521: yycg "userId =" yycg "password =" yycg "> </jdbcConnection> --> <! -- The default value is false. The jdbc decimal and NUMERIC types are parsed to Integer. If the value is true, the jdbc decimal and NUMERIC types are parsed to java. math. bigDecimal --> <javaTypeResolver> <property name = "forceBigDecimals" value = "false"/> </javaTypeResolver> <! -- TargetProject: location where the PO class is generated --> <javaModelGenerator targetPackage = "cn. zm. mybatis. po" targetProject = ". \ src"> <! -- EnableSubPackages: whether to use schema as the package suffix --> <property name = "enableSubPackages" value = "false"/> <! -- Space before and after the value returned from the database --> <property name = "trimStrings" value = "true"/> </javaModelGenerator> <! -- TargetProject: er ing file generation location --> <sqlMapGenerator targetPackage = "cn. zm. mybatis. mapper" targetProject = ". \ src"> <! -- EnableSubPackages: whether to use schema as the package suffix --> <property name = "enableSubPackages" value = "false"/> </sqlMapGenerator> <! -- TargetPackage: Location generated by the ER interface --> <javaClientGenerator type = "XMLMAPPER" targetPackage = "cn. zm. mybatis. mapper" targetProject = ". \ src"> <! -- EnableSubPackages: whether to use schema as the package suffix --> <property name = "enableSubPackages" value = "false"/> </javaClientGenerator> <! -- Specify a database table --> <table tableName = "items"> </table> <! -- <Table tableName = "orders"> </table> <table tableName = "orderdetail"> </table> <table tableName = "user"> </table> --> <! -- <Table schema = "" tableName = "sys_user"> </table> <table schema = "" tableName = "sys_role"> </table> <table schema = "" tableName "= "sys_permission"> </table> <table schema = "" tableName = "sys_user_role"> </table> <table schema = "" tableName = "sys_role_permission"> </table> --> <! -- Some table fields must specify the java type <table schema = "" tableName = ""> <columnOverride column = "" javaType = "/> </table> --> </ context> </generatorConfiguration>

3. Execute reverse engineering to generate code

Execute the java class method:

The generated code is as follows:

4. Copy the generated code to the Business System project for testing.

Public class ItemsMapperTest {private ApplicationContext applicationContext; private ItemsMapper itemsMapper; @ Before public void setUp () throws Exception {applicationContext = new ClassPathXmlApplicationContext ("classpath: applicationContext. xml "); itemsMapper = (ItemsMapper) applicationContext. getBean ("itemsMapper");} // Delete the Root primary key @ Test public void deleteByPrimaryKey () {itemsMapper. deleteByPrimaryKey (4) ;}@ Test public void insert () {}@ Test public void selectByExample () {ItemsExample itemsExample = new ItemsExample (); ItemsExample. criteria criteria = itemsExample. createCriteria (); // use criteria to customize the query condition criteria. andnamephoto to ("water cup"); criteria. andIdEqualTo (1); List <Items> list = itemsMapper. selectByExample (itemsExample); System. out. println (list) ;}@ Test public void selectByPrimaryKey () {Items items = itemsMapper. selectByPrimaryKey (1); System. out. println (items) ;}@ Test public void updateByPrimaryKey (){}}

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