Java MySQL查询中出现错误。检查行是否存在、更新或插入
下面的查询应该检查行是否存在,如果存在,则更新,如果不存在,则插入Java MySQL查询中出现错误。检查行是否存在、更新或插入,java,mysql,Java,Mysql,下面的查询应该检查行是否存在,如果存在,则更新,如果不存在,则插入 String sql = "IF EXISTS (SELECT * FROM 'mocha' WHERE uuid = " + uuid + ")" + "BEGIN" + "UPDATE 'mocha'" + "SET join_message = " + message + "WHERE uuid =" + uuid +
String sql = "IF EXISTS (SELECT * FROM 'mocha' WHERE uuid = " + uuid + ")" +
"BEGIN" +
"UPDATE 'mocha'" +
"SET join_message = " + message +
"WHERE uuid =" + uuid +
"END" +
"ELSE" +
"BEGIN" +
"INSERT INTO 'mocha' (uuid, join_message, quit_message)" +
"VALUES ('" + uuid + ", " + message + " + "" + "')" +
"END";
我希望能够在一个查询而不是两个查询中完成此操作,以下是整个方法:
public void setMessage(UUID uuid, String message) {
String sql = "IF EXISTS (SELECT * FROM 'mocha' WHERE uuid = " + uuid + ")" +
"BEGIN" +
"UPDATE 'mocha'" +
"SET join_message = " + message +
"WHERE uuid =" + uuid +
"END" +
"ELSE" +
"BEGIN" +
"INSERT INTO 'mocha' (uuid, join_message, quit_message)" +
"VALUES ('" + uuid + ", " + message + ", ''" + "')" +
"END";
BukkitRunnable r = new BukkitRunnable() {
@Override
public void run() {
System.out.println("Join message was set.");
try {
Statement statement = connection.createStatement();
statement.executeUpdate(sql);
} catch(SQLException e) {
e.printStackTrace();
}
}
};
r.runTaskAsynchronously(instance);
}
但是,我得到了以下错误:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''mocha' WHERE uuid = 0f9f822c-d7e6-4000-ac05-6ebc17b82f1d)BEGINUPDATE 'mocha'SET' at line 1
[10:18:52 WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[10:18:52 WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
[10:18:52 WARN]: at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
[10:18:52 WARN]: at java.lang.reflect.Constructor.newInstance(Unknown Source)
[10:18:52 WARN]: at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
[10:18:52 WARN]: at com.mysql.jdbc.Util.getInstance(Util.java:408)
[10:18:52 WARN]: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:943)
[10:18:52 WARN]: at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970)
[10:18:52 WARN]: at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906)
[10:18:52 WARN]: at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
[10:18:52 WARN]: at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677)
[10:18:52 WARN]: at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545)
[10:18:52 WARN]: at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1540)
[10:18:52 WARN]: at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2595)
[10:18:52 WARN]: at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1468)
[10:18:52 WARN]: at me.Latte.Models.MochaModel$2.run(MochaModel.java:68)
[10:18:52 WARN]: at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:71)
[10:18:52 WARN]: at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52)
[10:18:52 WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
[10:18:52 WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
[10:18:52 WARN]: at java.lang.Thread.run(Unknown Source)
我做错了什么?是的,您在表名周围使用单引号而不是反引号
mocha
。那么你的问题呢
INSERT INTO 'mocha'
应该是
INSERT INTO `mocha`
撇开其他问题不谈,您的SQL有一堆单词在一起运行,没有空格。打印出来并阅读。@khelwood是的,我现在意识到了这一点,我不知道我做错了什么。任何帮助都将不胜感激:@kinx您可能希望查看
替换到…
或插入到。。。在重复键上
谢谢,看起来我的整个队列都错了。我做错了什么?