C# MySQL 声称字段太长

Question

这是 SQL:

CREATE TABLE patients 
(
  patient_id INT AUTO_INCREMENT NOT NULL,
  last_name  VARCHAR(64) NOT NULL,
  first_name VARCHAR(64),
  sex        CHAR(1),
  birth      DATE,
  death      DATE,
  PRIMARY KEY (patient_id)
) ENGINE=INNODB;

这是 C#:

            MySqlCommand insertCom = new MySqlCommand("INSERT INTO patients(" +
                "last_name, first_name, sex, birth) VALUES" + 
                "('@lastName', '@firstName', '@sex', '@birthDate')",
                connection);

            /* ... */
            insertCom.Parameters.Add("@lastName", MySqlDbType.VarChar, 64);
            insertCom.Parameters.Add("@firstName", MySqlDbType.VarChar, 64);
            insertCom.Parameters.Add("@sex", MySqlDbType.Char, 1);
            insertCom.Parameters.Add("@birthDate", MySqlDbType.Date);

            insertCom.Parameters["@lastName"].Value = lastNameBox.Text; 
            insertCom.Parameters["@firstName"].Value = firstNameBox.Text;
            insertCom.Parameters["@sex"].Value = (sexBox.Text == "Male" ? 'M' : 'F');
            insertCom.Parameters["@birthDate"].Value = birthDatePicker.Text;

这是我在 SQL 中直接输入数据的方式:

INSERT INTO patients(last_name, first_name, sex, birth, death) 
VALUES
  ('DeLarge', 'Alexandra', 'F', '1975-12-02', NULL)

上面的工作，我写了基于它的 C# 代码。但是 C# 代码产生了这个:MySql.Data.MySqlClient.MySqlException:第 1 行“性别”列的数据太长。给了什么？

Answer 1

您不应该在参数名称周围使用单引号。试试这样:

MySqlCommand insertCom = new MySqlCommand("INSERT INTO patients(" +
            "last_name, first_name, sex, birth) VALUES" + 
            "(@lastName, @firstName, @sex, @birthDate)",
            connection);