PostgreSQL、Npgsql 返回 42601：“$1”处或附近的语法错误

Question

传递 PostgreSQL 命令时出现以下错误

42601: syntax error at or near ""

using (Npgsql.NpgsqlConnection conn = new Npgsql.NpgsqlConnection(DBManager.GetConnectionString()))
            {
                conn.Open();
                Logger.Info("connection opened for adding column");
                using (Npgsql.NpgsqlCommand addColumnQuery = new Npgsql.NpgsqlCommand(@"ALTER TABLE @tableName ADD COLUMN IF NOT EXISTS @columnName  @columnType;", conn))
                {
                    addColumnQuery.Parameters.AddWithValue("@tableName", tableName);
                    addColumnQuery.Parameters.AddWithValue("@columnName", columnName);
                    addColumnQuery.Parameters.AddWithValue("@columnType", columnType);
                    addColumnQuery.ExecuteNonQuery();
                }
            }

Answer 1

经过一些测试，我发现只有 table 值可以作为参数传递，而不是 table 名称和列名。所以我像这样更改了代码

ALTER TABLE tableName ADD COLUMN columnName columnType;

PostgreSQL、Npgsql 返回 42601：“$1”处或附近的语法错误

PostgreSQL, Npgsql returning 42601: syntax error at or near “$1”

c#

sql

sql-injection

npgsql

psql