org.springframework.jdbc.IncorrectResultSetColumnCountException: Incorrect column count

我就是我 2022-08-27 11:48 206阅读 0赞

使用springframework, JdbcTemplate对数据库进行查询时, 报出了**org.springframework.jdbc.IncorrectResultSetColumnCountException: Incorrect column count: expected 1, actual 2** 错误, 详细的Failure Trace如下:

org.springframework.jdbc.IncorrectResultSetColumnCountException: Incorrect column count: expected 1, actual 2
    	at org.springframework.jdbc.core.SingleColumnRowMapper.mapRow(SingleColumnRowMapper.java:88)
    	at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:93)
    	at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:60)
    	at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:708)
    	at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:644)
    	at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:695)
    	at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:727)
    	at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:737)
    	at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:805)
    	at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:824)
    	at org.springframework.jdbc.core.simple.SimpleJdbcTemplate.queryForObject(SimpleJdbcTemplate.java:159)
    	at com.apress.springrecipes.bank.JdbcAccountDao.findAccount(JdbcAccountDao.java:28)
    	at com.apress.springrecipes.bank.AccountServiceImpl.deposit(AccountServiceImpl.java:24)
    	at com.apress.springrecipes.bank.AccountServiceJUnit38LegacyTests6.testDeposit(AccountServiceJUnit38LegacyTests6.java:28)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:606)
    	at junit.framework.TestCase.runTest(TestCase.java:164)
    	at junit.framework.TestCase.runBare(TestCase.java:130)
    	at org.springframework.test.ConditionalTestCase.runBare(ConditionalTestCase.java:79)
    	at junit.framework.TestResult$1.protect(TestResult.java:106)
    	at junit.framework.TestResult.runProtected(TestResult.java:124)
    	at junit.framework.TestResult.run(TestResult.java:109)
    	at junit.framework.TestCase.run(TestCase.java:120)
    	at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
    	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

JdbcTemple.queryForObject 返回值类型是<T> T, 是单行单列一个数据, 也就是只能返回一个字段; 在检查程序后, 发现sql语句写的是SELECT \*, 而数据库表里有两列字段, 返回两列, 但是接收时却只有一个列, 就报出了这个incorrect column count的错误.

public Account findAccount(String accountNo) {
    		String sql = "SELECT * FROM ACCOUNT WHERE ACCOUNT_NO = ?";
    		double balance = getSimpleJdbcTemplate().queryForObject(sql,
    				Double.class, accountNo);
    		return new Account(accountNo, balance);
    	}
    修改后:
    public Account findAccount(String accountNo) {
    		String sql = "SELECT BALANCE FROM ACCOUNT WHERE ACCOUNT_NO = ?";
    		double balance = getSimpleJdbcTemplate().queryForObject(sql,
    				Double.class, accountNo);
    		return new Account(accountNo, balance);
    	}

再次运行, 一切正常.