如何在SQL select语句中设置列值？

Question

I want to set one column value in all rows to "0"

 SqlCommand cmd = m_objDbCAPEX.GetSqlCommand(CommandType.Text);

 cmd.CommandText = "SELECT CAPEX_BillOfMaterialItem.* FROM CAPEX_BillOfMaterialItem,CAPEX_BillOfMaterial WHERE CAPEX_BillOfMaterialItem.szBillOfMaterialId = CAPEX_BillOfMaterial.szBillOfMaterialId and CAPEX_BillOfMaterial.szProjectCode = '" + szProjectCode + "'";

 da = new SqlDataAdapter(cmd);
 da.Fill(dtDat);

Answer 1

You can try to set it like this:

select 0 as fieldName, col1, col2,...  from yourTable

In this case your fieldName column will be set as 0. ( You can replace the actual name of the column with fieldName )

Answer 2

Adding a point to @Rahul's answer.

If the field has specific values and if you want that alone to make it to 0 then you need CASE statements.

SELECT CASE 
         WHEN capex_billofmaterialitem.fieldname = 'checking value goes here' 
       THEN 0 
         ELSE capex_billofmaterialitem.fieldname 
       END AS fieldname1, 
       capex_billofmaterialitem.* 
FROM   capex_billofmaterialitem, 
       capex_billofmaterial 
WHERE  capex_billofmaterialitem.szbillofmaterialid = 
              capex_billofmaterial.szbillofmaterialid 
       AND capex_billofmaterial.szprojectcode = '" + szProjectCode + "'