① 關於sql查詢代碼。
同意「yj003 」的，可以改進一下：
select [欄位名], count(*) AS 數量 from [資料庫表名] where [欄位名] in (a, b, c ,d) group by [欄位名]
② SQL獲取表，欄位，類型的代碼
下面一段是SQLSERVER資料庫中獲取數據字典的語法，非常全。
SELECT TOP 100 PERCENT --a.id,
CASE WHEN a.colorder = 1 THEN d.name ELSE '' END AS 表名,
CASE WHEN a.colorder = 1 THEN isnull(f.value, '') ELSE '' END AS 表說明,
a.colorder AS 欄位序號, a.name AS 欄位名, CASE WHEN COLUMNPROPERTY(a.id,
a.name, 'IsIdentity') = 1 THEN '√' ELSE '' END AS 標識,
CASE WHEN EXISTS
(SELECT 1
FROM dbo.sysindexes si INNER JOIN
dbo.sysindexkeys sik ON si.id = sik.id AND si.indid = sik.indid INNER JOIN
dbo.syscolumns sc ON sc.id = sik.id AND sc.colid = sik.colid INNER JOIN
dbo.sysobjects so ON so.name = si.name AND so.xtype = 'PK'
WHERE sc.id = a.id AND sc.colid = a.colid) THEN '√' ELSE '' END AS 主鍵,
b.name AS 類型, a.length AS 長度, COLUMNPROPERTY(a.id, a.name, 'PRECISION')
AS 精度, ISNULL(COLUMNPROPERTY(a.id, a.name, 'Scale'), 0) AS 小數位數,
CASE WHEN a.isnullable = 1 THEN '√' ELSE '' END AS 允許空, ISNULL(e.text, '')
AS 默認值, ISNULL(g.[value], '') AS 欄位說明, d.crdate AS 創建時間,
CASE WHEN a.colorder = 1 THEN d.refdate ELSE NULL END AS 更改時間
FROM dbo.syscolumns a LEFT OUTER JOIN
dbo.systypes b ON a.xtype = b.xusertype INNER JOIN
dbo.sysobjects d ON a.id = d.id AND d.xtype = 'U' AND
d.status >= 0 LEFT OUTER JOIN
dbo.syscomments e ON a.cdefault = e.id LEFT OUTER JOIN
dbo.sysproperties g ON a.id = g.id AND a.colid = g.smallid AND
g.name = 'MS_Description' LEFT OUTER JOIN
dbo.sysproperties f ON d.id = f.
id AND f.smallid = 0 AND
f.name = 'MS_Description'
ORDER BY d.name, a.colorder
③ SYBASE 中 SQL 代碼取 所有表的前10行
use sybsystemprocs
go
if exists(select 1 from dbo.sysobjects where name='sp_list_topN_rows' and type='P' )
drop proc sp_list_topN_rows
go
create proc sp_list_topN_rows @num_rows int=null
as
begin
declare @tablename varchar(30),@tablename_prev varchar(30),@sqltext varchar(255)
if (@num_rows is null)
select @num_rows = 10
select top 1 @tablename=name from sysobjects where type='U' order by name
while (@tablename is not null)
begin
select @sqltext="select top " || convert(varchar,@num_rows) || " * from " || @tablename
exec(@sqltext)
select @tablename_prev =@tablename,@tablename=NULL
select top 1 @tablename=name from sysobjects where type='U' and name > @tablename_prev order by name
end
end
go
④ C#中關於sql查詢的代碼怎麼寫
string Con = "server=GRQ;uid=;pwd=;database=111 ;";
SqlConnection ConnSql = new SqlConnection( loveDataSet ); //Sql鏈接類的實例化
ConnSql.Open();//打開資料庫
string strSQL = "select * from zong where sign like ' "%+ 文本框里的值 +%"' "; //要執行的SQL語句
SqlDataAdapter da = new SqlDataAdapter(strSQL, ConnSql); //創建DataAdapter數據適配器實例
DataSet ds = new DataSet();//創建DataSet實例
da.Fill(ds, "自定義虛擬表名");
//使用DataAdapter的Fill方法(填充)，調用SELECT命令
dataGridView1.DataSource = ds.Tables[1].DefaultView;
ConnSql.Close();//關閉資料庫
⑤ 關於sql資料庫查詢代碼！
假設你這個表有兩個欄位id(自動增長),name(姓名)，現在要取姓名最後一個數據，可以這樣寫：
select top 1 name from tablename order by id desc
⑥ 如何用SQL代碼提取文件名中的字元後插入表中
存儲過程,一個下劃線一個下劃線切.切完馬上存到表裡.
步驟:
1.替換後綴
列3 列1 列2
AA1_BB2_CC3
-----------------
2.取第一個下劃線前的數據
列3 列1 列2
AA1_BB2_CC3 AA1
-----------------
3.刪除列1長度的數據
列3 列1 列2
BB2_CC3 AA1
-----------------
4.取第二下劃線數據
列3 列1 列2
BB2_CC3 AA1 BB2
-----------------
列3 列1 列2
CC3 AA1 BB2
-----------------
⑦ 求查詢SQL語句代碼
你好，SQL語句如下
select NAME,ADDRESS from C表 where NAME in
(select NAME from A表 where NAME not in
(select NAME from B表)
)
簡單說明一下：
最外層是直接搜索「姓名，地址」，對NAME有要求
中間一層是搜索在A表中出現的NAME
最內層是排除在A表中出現但又不在B表中的NAME
⑧ C# 求獲取Sql各項的正則表達式代碼
sql的語法雖然我們平時用的就像 select * from [admin] where id = 2 這句一樣，其實還有很多其他的語法也能做到的。
所以這個正則也只能是針對常規的簡單SQL語句。
我寫了一個，也只是判斷了一些常用的SQL關鍵字。僅作為參考。
string text = "select * from [admin] where aa=1 and cc='b' order by aa desc ";
Regex reg = null;
reg = new Regex(@"\s+from\s+.*?(\s+where\s+|\s+order\s+|\s+group\s+)|\s+from\s+.+", RegexOptions.IgnoreCase);
string table = reg.Match(text).Value;
table = Regex.Replace(table.ToLower(), @"\s+from\s+|\s+where\s+|\[|\]|\s+order\s+|\s+group\s+", "");
reg = new Regex(@"select\s+.*?\s+from\s+", RegexOptions.IgnoreCase);
string field = reg.Match(text).Value;
field = Regex.Replace(field.ToLower(), @"select\s+|\s+from\s+|\[|\]", "");
reg = new Regex(@"\s+where\s+.*?(\s+order\s+|\s+group\s+)|\s+where\s+.+", RegexOptions.IgnoreCase);
string condition = reg.Match(text).Value;
condition = Regex.Replace(condition.ToLower(), @"\s+where\s+|\s+order\s+|\s+group\s+|\[|\]", "");
reg = new Regex(@"\s+order\s+by\s+.*?\s(desc|asc)|\s+order\s+by\s+.*?\s", RegexOptions.IgnoreCase);
string order = reg.Match(text).Value;
order = Regex.Replace(order.ToLower(),@"\s+order\s+by\s+|\[|\]", "");
還有問題可以追問或者HI我。~
⑨ 什麼是sql 代碼
sql代碼是用代碼操作資料庫，從資料庫里把數據取出來，加進去。