Question

对于以下SQL select语句; -

resultSet = statement.executeQuery("SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER," +" SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
"FROM  PERSON, ORDERS " +
"WHERE SS100.PERSON.PERSON_ID = SS100.ORDERS.PERSON_ID " );

我在WHERE关键字上遇到语法错误 - 转储如下： -

 java.sql.SQLSyntaxErrorException: Syntax error: Encountered "WHERE" at line 1, column 126.
    at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedStatement.executeQuery(Unknown Source)
    at Database.orderQuery(Database.java:146)
    at MainApp.main(MainApp.java:19)

Caused by: java.sql.SQLException: Syntax error: Encountered "WHERE" at line 1, column 126.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)... 10 more

我尝试过使用alias语句，但是然后在'。'上出错。点运算符。我显然做了一些根本错误的事情，但我现在看不到它，有人可以帮忙吗？

Answer 1

看这里：

resultSet = statement.executeQuery("SELECT ..." +... + " SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
    "FROM  PERSON, ORDERS " +

"SS100.PERSON.FIRST_NAME"和"FROM"之间没有空格。

通过始终用空格启动零件可以轻松解决这个问题：

resultSet = statement.executeQuery("SELECT ..." +... + " SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
    " FROM  PERSON, ORDERS " +
    " WHERE ..."

Answer 2

这个字符串串联将变为

"SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER," +" SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+

“来自人，订单”+ “WHERE SS100.PERSON.PERSON_ID = SS100.ORDERS.PERSON_ID”

SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER, SS100.ORDERS.PERSON_ID,
SS100.PERSON.FIRST_NAMEFROM  PERSON, ORDERS WHERE SS100.PERSON.PERSON_ID =
SS100.ORDERS.PERSON_ID

问题出在FIRST_NAME和FROM加入的地方。在FIRST_NAME之后添加一个空格，sql运行正常。

但是，你应该问自己为什么要这样做。如果您知道要连接的值，为什么不能开始使用一个字符串。

使用apache Derby的WHERE子句上的SQL语法错误

2 个答案: