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using System;
using System.Collections;
using System.Collections.Specialized;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace DAL
{
public class DataControl
{
public static string connectionString = "server=" + SystemSet.getServerSet_ServerIP() + ";uid=" + SystemSet.getServerSet_ServerUser() + ";pwd=" + SystemSet.getServerSet_ServerPass() + ";database=" + SystemSet.getServerSet_ServerDataBase() + "";
/// <summary>
/// ³õʼ»¯ /// </summary>
public DataControl()
{
}
/// <summary>
/// ÎÞ²ÎÊý£¬²âÊÔÊý¾Ý¿âÁ¬½ÓÊÇ·ñÉèÖúÏÀí¡£ /// </summary>
/// <returns>ÊÇ·ñÁ¬½Ó³É¹¦</returns>
public static bool checkconn()
{
try
{
SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
return true;
}
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Oracle SQL(partI)
Data manipulation language(DML): select, insert, update, delete, merge.
Data definition language(DDL): create, alter, drop, rename, truncate, comment
Data control language(DCL): grant, revoke
Transaction control: commit, rollback, savepoint
Arithmetic Expressions:
+, -, *, / ......
Subquery: (single-row subqueries and multi-rows subqueries).
select select_list
from table
where expr operator (select select_list from table);
single-row subqueries operator: =, >, >=, <, <=, <>
e.g.:
1. select department_id, min(salary) from employees group by department_id ......
oracle tips
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