C# SQL update query

Legent Mady

i am using visual studio 2015,

update command using sql command

string sql = "UPDATE STU set PRESENTEDHOURS=PRESENTEDHOURS + 5,TOTALHOURS=TOTALHOURS + 5 WHERE DEPARTMENT='COMPUTER SCIENCE' AND COURSE='" + comboBox1.Text.ToString() + "' AND YEAR='" + comboBox2.Text.ToString() + "' AND SHIFT='" + comboBox3.Text.ToString() + "'";

but updated presented hours and total hours 10 values

3 Replies

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Nilesh Shah9y ago
Accepted answer
May be these columns already had a value of 5?

Or may be your query is being fired two times?

Reset both values to zero, and check again

If it is on development machine, try to put a debug point and see what happens

otherwise you need to write a before update and after update trigger to see what actually happens on SQL server
Legent Mady9y ago
database name : lib
table name : stu
colummns : reg no(varchar)
presented hours(int)
total no of hours (int)
percentage(float)

i am using vs2015 language : c#

my update presented houres,totalhours query is

string sql = "UPDATE STU set PRESENTEDHOURS=PRESENTEDHOURS + 5,TOTALHOURS=TOTALHOURS + 5 WHERE DEPARTMENT='COMPUTER SCIENCE' AND COURSE='" + comboBox1.Text.ToString() + "' AND YEAR='" + comboBox2.Text.ToString() + "' AND SHIFT='" + comboBox3.Text.ToString() + "'";

but presented hours added 10 and total hours add 10
Nilesh Shah9y ago
What is exactly your problem?

You need to specify problem clearly