问题与数据库有关 [英] problem realated to database

问题描述

如何在数据库中检查单行是否存在c＃ms access

how we can check single row exist or not in database in c# ms access

推荐答案

编写查询（ Google是您的朋友 [ ^ ]）并检查结果。

Write a query (Google is your friend[^]) and check the result.

试试这个代码

try this code

qry = "select * from department_master where dep_code='" + txt.Text + "'";
sql_cmd = new SqlCommand(qry, sql_con);
sql_con.Open();
sql_rs = sql_cmd.ExecuteReader();
if (sql_rs.Read())
{
    //exists
}
else
{
    //not exists
}
sql_rs.Close();
sql_con.Close();

Hai

首先，您使用数据库中的选择数据并填入数据表，并检查行数，如果它高于1，那么数据库有行，使用select查询的条件然后只有你找到确切的数据退出。

for examble

Hai
First u have use select data from database and fill into data table,and check row count,if it is above 1 then database have row,use where condition for select query then only u find exact data exit or not.
for examble

OleDbConnection cn;
OleDbCommand cmd2;
cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" your dbpath herer ";Jet OLEDB:");
cn.Open();
OleDbDataAdapter objDA = new OleDbDataAdapter("select * from Users where UserId='007'", cn);
DataTable objDT = new DataTable();
objDA.Fill(objDT);
if ((objDT.Rows.Count == 1)) {
    // database have row
}

以上代码从表中选择精确数据，这里用户是表，但是你想要数据库有没有数据

试试这样

the above code for select exact data from table,here users is table,but u want database have data or not
try like this

OleDbConnection cn;
OleDbCommand cmd2;
cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" your dbpath herer ";Jet OLEDB:");
cn.Open();
OleDbDataAdapter objDA = new OleDbDataAdapter("select * from Users", cn);
DataTable objDT = new DataTable();
objDA.Fill(objDT);
if ((objDT.Rows.Count == 1)) {
    // database have row
}

问候

Aravind

Regards
Aravind

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