SQLite與MySql、Oracle的使用區別(C#)
阿新 • • 發佈:2019-02-05
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