我有这段代码,我想让它变成 varchar 而不是字符串。在 c# 中执行此操作的适当语法是什么
string emri = row["Nome"].ToString();
我有一个必须运行的查询,我在其中使用 emri 并将它与我在 mysql 中创建的表中的列进行比较。mysql 中的列是 varchar(20) 类型。当我执行我的代码时,它在我的查询中给出了一个错误,我猜可能是因为这个原因
I have this query
string query = "IF NOT EXISTS(SELECT * FROM clienti WHERE CodCliente= " + id + " AND Nome = '" + emri + "' AND RagioneSociale=' " + ragSoc + " ' AND PartitaIVA=' " + piva + " ') INSERT INTO clienti VALUES(" + id + " ,' " + emri + " ',' " + ragSoc + " ',' " + piva + " ') else UPDATE clienti SET( " + id + " ,' " + emri + " ',' " + ragSoc + " ',' " + piva + " ')";
它给了我这个问题
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IF NOT EXISTS(SELECT * FROM clienti WHERE CodCliente= 1 AND NomeCliente = 'Jo' at line 1