为什么即使没有插入新行,executeUpdate仍返回1? [英] why does executeUpdate return 1 even if no new row has been inserted?
问题描述
这是我非常简单的表格(Postgres):
here is my very simple table (Postgres):
CREATE TABLE IF NOT EXISTS PERFORMANCE.TEST
(
test text NOT NULL UNIQUE
);
如果我尝试使用下面的命令从数据库中插入字符串,那么一切都会按预期进行,因此,毫无疑问,数据库中会出现新的一行.
if I try to insert a String using the command below FROM the database,everything works as expected, not surprisingly a new row appears in the DB.
insert into performance.test (test) values ('abbbbaw');
但是,如果我想通过JDBC插入字符串,则不会插入任何内容,尽管prepareStatement.executeUpdate()始终返回1.
However if I want to insert a String through JDBC, nothing gets inserted, although preparedStatement.executeUpdate() always returns 1.
下面是我应该使用的方法,但是没有用.如果我缺少明显的东西,请告诉我. 我想补充一点,就是我从没有得到任何SQLException.
Below is my method that should be working but it does not. Please tell me if I am missing something obvious. I want to add that I never get any SQLException.
private void storePerformance() {
Connection conn= initializePerformanceConnection();
if (conn!= null) {
PreparedStatement insertPS = null;
try {
insertPS = conn.prepareStatement("insert into performance.test (test) values (?)");
insertPS.setString(1, queryVar);
int i = insertPS.executeUpdate();
LogManager.doLog(LOG, LOGLEVEL.INFO," numberofrows= "+i);
} catch (SQLException e) {
LogManager.doLog(LOG, LOGLEVEL.INFO,"Inserting query failed = "+queryVar,e);
}finally{
if(insertPS != null){
try {
insertPS.close();
} catch (SQLException e) {
LogManager.doLog(LOG, LOGLEVEL.INFO,"Closing PreparedStatement failed = "+queryVar,e);
}
}
try {
conn.close();
} catch (SQLException e) {
LogManager.doLog(LOG, LOGLEVEL.INFO,"Closing performanceConnection failed= "+ queryVar, e);
}
}
}
}
推荐答案
所缺少的:
conn.commit();
(在executeUpdate()之后)
(after the executeUpdate())
实际上插入了新行,但数据库立即回滚.
actually a new row was inserted but the DB rolled back immediately.
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