SQL没有将文件内容添加到表中

Question

目前我正在尝试通过 Apache Derby 将新数据传递给 SQL 表。我要从具有给定文本的文件中读取，并将读取的每个标记添加到其各自的列中。

但是，在尝试执行此操作时，我收到许多错误，表明令牌不是列...但这不是我想要做的。

carmpg.txt 内容：

Toyota  Prius   52  23475
Kia Optima  31  22600
Hyundai     Sonata  31  22050
Nissan  Altima  31  23260
Chevrolet   Malibu  30  21680
Honda   Accord  30  23570
Mazda   6   29  21945
Subaru  Legacy  29  22195
Toyota  Camry   27  23495
Chrysler    200 27  22115
Ford    Fusion  27  22120
Volkswagen  Passat  27  22995
Volkswagen  CC  25  34475
Chevrolet   Impala  25  27895
Buick   LaCrosse    25  29565
Nissan  Maxima  25  33270
Buick   Regal   24  27065
Lincoln MKZ 26  3560

所以，Toyota 应该进入 Manufacturer 列，Prius 应该进入 Model 列，依此类推。

代码如下：

 try(Connection conn = SimpleDataSource.getConnection();Statement stat = 
conn.createStatement()) 
  {
     try
     {
        stat.execute("DROP TABLE Car");
     }
     catch(SQLException e)
     {
         // get exception if table doesn't exist yet
     }

     stat.execute("CREATE TABLE Car (Manufacturer VARCHAR(20),"
           + "Model VARCHAR(20), " + "Efficiency DECIMAL(6,2), " + "Price DECIMAL(8,2)) ");


     String inputFileName = "carmpg.txt";
     File inputFile = new File(inputFileName);
     Scanner in = new Scanner(inputFile);

     // COMPLETE THIS WHILE LOOP to insert all cars from the input text file
     while (in.hasNextLine()){

         stat.execute("INSERT INTO Car VALUES " + in.next());


     }

     ResultSet rs = stat.executeQuery("SELECT * FROM Car");
     rs.next();
     System.out.println(rs.getString("Model"));

以及相关的stacktrace：

Exception in thread "main" java.sql.SQLSyntaxErrorException: Column 'TOYOTA' 
is either not in any table in the FROM list or appears within a join 
specification and is outside the scope of the join specification or appears 
in a HAVING clause and is not in the GROUP BY list. If this is a CREATE or 
ALTER TABLE  statement then 'TOYOTA' is not a column in the target table.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.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.execute(Unknown Source)
at CarDB.main(CarDB.java:49)
Caused by: ERROR 42X04: Column 'TOYOTA' is either not in any table in the 
FROM list or appears within a join specification and is outside the scope of 
the join specification or appears in a HAVING clause and is not in the GROUP 
BY list. If this is a CREATE or ALTER TABLE  statement then 'TOYOTA' is not a 
column in the target table.
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.impl.sql.compile.ColumnReference.bindExpression(Unknown 
Source)
at org.apache.derby.impl.sql.compile.ColumnReference.bindExpression(Unknown 
Source)
at org.apache.derby.impl.sql.compile.ResultColumn.bindExpression(Unknown 
Source)
at org.apache.derby.impl.sql.compile.ResultColumnList.bindExpressions(Unknown 
Source)
at org.apache.derby.impl.sql.compile.RowResultSetNode.bindExpressions(Unknown 
Source)
at org.apache.derby.impl.sql.compile.DMLStatementNode.bindExpressions(Unknown 
Source)
at org.apache.derby.impl.sql.compile.InsertNode.bindStatement(Unknown Source)
at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown Source)
at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown Source)
at org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(Unknown Source)
... 3 more

感谢您的帮助

Answer 1

INSERT INTO 语句的语法是：

INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);

另外，您的错误是您尝试从文本文件中插入整行而不将其分成代表 4 个不同列的 4 个部分。
你得到的错误被触发是因为你试图执行这个无效的语句：

INSERT INTO Car VALUES Toyota Prius   52  23475

应该是

INSERT INTO Car (Manufacturer, Model, Efficiency, Price) VALUES ('Toyota', 'Prius', 52, 23475)