1.引數

SQLiteParameter p = new SQLiteParameter(":project_id", DbType.String);
p.Value = project_id;

 MySqlParameter p = new MySqlParameter("?project_id", MySqlDbType.VarChar);
 p.Value = project_id;

 OracleParameter p = new OracleParameter(":project_id", OracleDbType.Varchar2);
 p.Value = project_id;
 

2.引數型別

SQLite引數型別通過DbType設定，MySql引數型別通過MySqlDbType設定，Oracle引數型別通過OracleDbType配置愛

SQLite引數 ：

SQLiteParameter[] p = {
                    new SQLiteParameter(":project_id", DbType.String),
                    new SQLiteParameter(":project_name", DbType.String),
                    new SQLiteParameter(":project_outer_name", DbType.String),
                    new SQLiteParameter(":project_status", DbType.String),
                    new SQLiteParameter(":project_type",DbType.String),
                    new SQLiteParameter(":hardware_platform",DbType.String),
                    new SQLiteParameter(":platform_model",DbType.String),
                    new SQLiteParameter(":leader_name",DbType.String)
}
p[0]=project_id;
...
 

MySql引數： 

MySqlParameter[] p = {
                  //MySQL傳參格式為:?引數
		        new MySqlParameter("?project_id", MySqlDbType.VarChar),
	            new MySqlParameter("?project_name", MySqlDbType.VarChar),
                new MySqlParameter("?project_outer_name", MySqlDbType.VarChar),
		        new MySqlParameter("?project_status", MySqlDbType.VarChar),
		        new MySqlParameter("?project_type",MySqlDbType.VarChar),
                new MySqlParameter("?hardware_platform",MySqlDbType.VarChar),
                new MySqlParameter("?platform_model",MySqlDbType.VarChar),
                new MySqlParameter("?leader_name",MySqlDbType.VarChar)
}
p[0]=project_id;
...
 

Oracle引數：

OracleParameter[] p = {
                     new OracleParameter("?project_id", OracleDbType.Varchar2，10),
	                new OracleParameter("?project_name", OracleDbType.Varchar2),
                    new OracleParameter("?project_outer_name", OracleDbType.Varchar2),
		            new OracleParameter("?project_status",OracleDbType.Varchar2),
		            new OracleParameter("?project_type",OracleDbType.Varchar2),
                    new OracleParameter("?hardware_platform",OracleDbType.Varchar2),
                    new OracleParameter("?platform_model",OracleDbType.Varchar2),
                    new OracleParameter("?leader_name",OracleDbType.Varchar2)
					
                                   };
p[0]=project_id;
...

SQL的Left Join、Right Join 和Inner Join

Left join(左聯接)：返回包括左表中的所有記錄和右表中聯結欄位相等的記錄 
Right join(右聯接) ：返回包括右表中的所有記錄和左表中聯結欄位相等的記錄
Inner join(內連線)： 只返回兩個表中聯結欄位相等的行