Question

我想在动态SQL查询中设置表名。我成功尝试参数如下：

/* Using sp_executesql */
/* Build and Execute a Transact-SQL String with a single parameter 
value Using sp_executesql Command */

/* Variable Declaration */
DECLARE @EmpID AS SMALLINT
DECLARE @SQLQuery AS NVARCHAR(500)
DECLARE @ParameterDefinition AS NVARCHAR(100)
/* set the parameter value */
SET @EmpID = 1001
/* Build Transact-SQL String by including the parameter */
SET @SQLQuery = 'SELECT * FROM tblEmployees WHERE EmployeeID = @EmpID' 
/* Specify Parameter Format */
SET @ParameterDefinition =  '@EmpID SMALLINT'
/* Execute Transact-SQL String */
EXECUTE sp_executesql @SQLQuery, @ParameterDefinition, @EmpID

现在我想使用参数动态获取TABLE NAME，但我没有这样做。请指导我。

Answer 1

表名不能作为参数提供，因此您必须像这样手动构造SQL字符串：

SET @SQLQuery = 'SELECT * FROM ' + @TableName + ' WHERE EmployeeID = @EmpID'

但是，请确保您的应用程序不允许用户直接输入@TableName的值，因为这会使您的查询容易受到SQL注入的影响。有关此问题的一种可能解决方案，请参阅this answer。

Answer 2

为了防止SQL注入，我通常会尝试尽可能使用函数。在这种情况下，你可以这样做：

...
SET @TableName = '<[db].><[schema].>tblEmployees'
SET @TableID   = OBJECT_ID(TableName) --won't resolve if malformed/injected.
...
SET @SQLQuery = 'SELECT * FROM ' + OBJECT_NAME(@TableID) + ' WHERE EmployeeID = @EmpID'

Answer 3

试试这个：

/* Variable Declaration */
DECLARE @EmpID AS SMALLINT
DECLARE @SQLQuery AS NVARCHAR(500)
DECLARE @ParameterDefinition AS NVARCHAR(100)
DECLARE @TableName AS NVARCHAR(100)
/* set the parameter value */
SET @EmpID = 1001
SET @TableName = 'tblEmployees'
/* Build Transact-SQL String by including the parameter */
SET @SQLQuery = 'SELECT * FROM ' + @TableName + ' WHERE EmployeeID = @EmpID' 
/* Specify Parameter Format */
SET @ParameterDefinition =  '@EmpID SMALLINT'
/* Execute Transact-SQL String */
EXECUTE sp_executesql @SQLQuery, @ParameterDefinition, @EmpID

Answer 4

以@ user1172173的先前答案为基础，该答案解决了SQL Injection漏洞，请参见下文：

CREATE PROCEDURE [dbo].[spQ_SomeColumnByCustomerId](
@CustomerId int,
@SchemaName varchar(20),
@TableName nvarchar(200)) AS
SET Nocount ON
DECLARE @SQLQuery AS NVARCHAR(500)
DECLARE @ParameterDefinition AS NVARCHAR(100)
DECLARE @Table_ObjectId int;
DECLARE @Schema_ObjectId int;
DECLARE @Schema_Table_SecuredFromSqlInjection NVARCHAR(125)

SET @Table_ObjectId = OBJECT_ID(@TableName)
SET @Schema_ObjectId = SCHEMA_ID(@SchemaName)
SET @Schema_Table_SecuredFromSqlInjection = SCHEMA_NAME(@Schema_ObjectId) + '.' + OBJECT_NAME(@Table_ObjectId)

SET @SQLQuery = N'SELECT TOP 1 ' + @Schema_Table_SecuredFromSqlInjection + '.SomeColumn 
FROM dbo.Customer 
INNER JOIN ' + @Schema_Table_SecuredFromSqlInjection + ' 
ON dbo.Customer.Customerid = ' + @Schema_Table_SecuredFromSqlInjection + '.CustomerId 
WHERE dbo.Customer.CustomerID = @CustomerIdParam 
ORDER BY ' + @Schema_Table_SecuredFromSqlInjection + '.SomeColumn DESC' 
SET @ParameterDefinition =  N'@CustomerIdParam INT'

EXECUTE sp_executesql @SQLQuery, @ParameterDefinition, @CustomerIdParam = @CustomerId; RETURN

Answer 5

这是动态获取模式并将其添加到数据库中不同表中以动态获取其他信息的最佳方法

select @sql ='插入#tables SELECT''[''+ SCHEMA_NAME（schema_id）+''。''+ name +'']''AS SchemaTable from sys.tables'

exec (@sql)

当然#tables是存储过程中的动态表

如何在动态SQL查询中设置表名？

5 个答案: