修复异常 System.Data.SqlClient.SqlException: '''''附近的语法不正确。'

Question

When I run the ide show the following exception

System.Data.SqlClient.SqlException: 'Incorrect syntax near '='.'

string query = "SELECT * FROM lwpos_categories  WHERE parent_id=" + ddlCategory.SelectedValue;

Answer 1

Probably ddlCategory.SelectedValue is empty. The following can fix this exception (and I recommend using SqlParameters ).

string query = "SELECT * FROM lwpos_categories  WHERE parent_id= '" + ddlCategory.SelectedValue + "'";