如何为java预处理语句插入[duplicate]使用tablename变量

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Using Prepared Statements to set Table Name 6 answers
使用Prepared Statements设置表名6答案

I am using a java PreparedStatment object to construct a series of batched INSERT queries. The query statement is of the format...

我正在使用java PreparedStatment对象来构造一系列批量INSERT查询。查询语句的格式为......

String strQuery = "INSERT INTO ? (col1, col2, col3, col4, col5) VALUES (?,?,?,?,?,?);";

...so both field values and the tablename are variables (ie. I have multiple tables with the same column format of which each insert will be directed to a different one). I can get the executes to work if I remove the "?" tablename variable and hard code but each prepared statement will be inserted into a different table so needs to remain a variable I populate immediately prior to executing the batch query using...

...所以字段值和表名都是变量（即，我有多个表格具有相同的列格式，每个表格将定向到另一个表格）。如果我删除“？”，我可以让执行工作tablename变量和硬代码，但每个预处理语句将被插入到不同的表中，因此需要保留一个变量，我在执行批处理查询之前立即填充...

stmt.setString(1, "tableName1");

How can I let this be a dynamic variable please?

我怎么能让这个变成动态变量呢？

5 个解决方案

#1

You can't. You need to contruct the sql with string concatenation/placeholder with String.format. prepared statement is for the column values not for table name.

你不能。您需要使用字符串连接/占位符和String.format构造sql。预准备语句用于列值而不是表名。

#2

You can use placeholder in place of table name and then replacing that with your tablename.

您可以使用占位符代替表名，然后将其替换为您的表名。

String strQuery = "INSERT INTO $tableName (col1, col2, col3, col4, col5)
                   VALUES (?,?,?,?,?,?);";

and replace when u come to know the tablename

当你知道tablename时替换

String query =strQuery.replace("$tableName",tableName);
stmt =conn.prepareStatement(query);

#3

-1

One alternative could be String.format:

一种替代方案可以是String.format：

e.g.

例如

String sql = String.format("INSERT INTO $1%s (col1, col2, col3, (etc)",  myTablename);

#4

-2

The table name can't be used as a parameter. It must be hard coded. Try something like:

表名不能用作参数。它必须是硬编码的。尝试以下方法：

String tableName = "tableName1";
String strQuery = "INSERT INTO " + tableName + " (col1, col2, col3, col4, col5) VALUES (?,?,?,?,?,?);";

#5

-3

You would need to add it to the original string:

您需要将其添加到原始字符串：

String tableName = "some_table_name";
// some other code
String strQuery = "INSERT INTO " + tableName + " (col1, col2, col3, col4, col5) VALUES (?,?,?,?,?,?);";

Do you need the semi-colon in the strQuery? (you may do, it just looks a bit weird to me :-))

你需要在strQuery中使用分号吗？（你可能会这样，对我来说看起来有点奇怪:-)）

#1