java - com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException | JAVA

Question

我想在我的 java 项目中获取表中的条目数。

这是我的代码:

int count = 0;
Statement st = Mysql.con.createStatement();
ResultSet rs= st.executeQuery("select count(*) from keys where spieler =" +p.getName());
while (rs.next()){
    count = rs.getInt(1);
}

我得到以下 SQLEXCEPTION:

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 'keys where spieler =Pit910' at line 1

什么是磨损？

谢谢!

Answer 1

keys 是一个 reserved MySQL keyword需要转义(那个或 ALTER 表以给它一个不同的名称)。试试这个

PreparedStatement preparedStatement = 
    con.prepareStatement("select count(*) from `keys` where spieler = ?");
preparedStatement.setString(1, p.getName());
ResultSet rs= preparedStatement.executeQuery();
...