Creating a table programmatically using MyBatis and MySql

MarMan picture MarMan · Aug 28, 2015 · Viewed 11.1k times · Source

I want to create a method to dynamically create tables just passing the table name as a variable. I have defined my xml mapper

<mapper namespace="com.mappers.TableCreatorMapper">
    <cache />
    <insert id="createNewTableIfNotExists" parameterType="String" > 
        CREATE TABLE IF NOT EXISTS #{tableName} 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB
    </insert>
</mapper>

And my Java Interface Mapper is simply:

public interface TableCreatorMapper {
     public void createNewTableIfNotExists(String tableName);
}

but when I call my interface

tableCreatorMapper.createNewTableIfNotExists("test");

I get the following exception:

org.springframework.jdbc.BadSqlGrammarException: 
### Error updating database.  Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
### The error may involve com.mappers.TableCreatorMapper.createNewTableIfNotExists-Inline
### The error occurred while setting parameters
### SQL: CREATE TABLE IF NOT EXISTS ?          (         `ID` varchar(20) NOT NULL,         PRIMARY KEY (`ID`)         )    ENGINE=InnoDB
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
    at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:231)
    at org.sp

If I instead change the query adding the ``for the table name:

 CREATE TABLE IF NOT EXISTS `#{tableName}`(
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB

I get

### The error occurred while setting parameters
### SQL: CREATE TABLE IF NOT EXISTS `?`(         `ID` varchar(20) NOT NULL,         PRIMARY KEY (`ID`)         )    ENGINE=InnoDB
### Cause: java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).
; SQL []; Parameter index out of range (1 > number of parameters, which is 0).; nested exception is java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).

Any idea why?

Answer

agad picture agad · Aug 28, 2015

try

CREATE TABLE IF NOT EXISTS ${_parameter} 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB

#{name} is for parameters in PreparedStatement (see String Substitution in Parameters).