添加多个输入以查询 MS SQL 使用“node-mssql”的服务器实例 npm package

Question

I would like to query MS SQL Server instance to serve a very simple POST request. I am using nodejs + express. The following code (async version) considers only first input types only and therefore returns error -

  let pool = await sql.connect(dbCredentials);
  let bookName = "string to be matched" ; 
  let ranksVal= 10
  
  let result = await pool
    .request()
    .input("item", sql.VarChar, bookName)
    .input("ranksVal", sql.Int , ranksVal)
    .query(`select top @ranksVal * from dbTable where book = @item order by counts desc`);

Ideally, the above code should return a result for the following SQL query:

 select top 10 * from dbTable where book = "string to be matched" order by counts desc

Alternatively, the following solution works:

  let result = await pool
    .request()
    .input("item", sql.VarChar, bookName)
    .query(`select top ${ranksVal} * from dbTable where book = @item order by counts desc`);

But I would like to understand how can we pass multiple values to req.input() method. Thank you.

Answer 1

To use an expression or a parameter in a TOP values clause you must use parentheses. eg

 .query(`select top (@ranksVal) * from dbTable where book = @item order by counts desc`);