DataSource Controls :: SQL Server SELECT Statement Is Slow In Large Tables?
Jun 1, 2010
I'm facing a problem in our current running application. There is a table in database which has 67 columns,among these 18 columns are nvarchar(max) datatype and contains 30K records. Problem is now that SELECT * FROM myTable it takes around 3 to 4 seconds. Which is degrading our application's performance.
I want to select the number of goals, assist and cards a player has in a specific tournament. I tried with this query but then the goal and card column shows the sum of the number of rows matching the playerid in the Goal table and the Card table...For example if there is two matching rows in the goal table and three matching rows in the card table, I get 5 in both these columns in the resultset.
SELECT u.Email FROM UserProfiles p, aspnet_Membership u WHERE p.RulesCheckBox = 'True' AND u.UserId = p.UserId This gives me a list of registered member email addresses that have selected the RulesCheckBox in their profile, so I can email them with an email script. There is a relationship between the Membership table and the UserProfile table, so it finds the email addresses from the Membership table where that user has the RulesCheckBox checked in their profile (in UserProfiles table). I'm wanting to add some additional names to this list, from a different table. The purpose is so I can manually add email addresses to the additional table, so the additional email addresses will also receive the same email, even though they aren't registered members of the site. So how can I adjust that SELECT statement so this one is combined with it somehow?:
SELECT Email FROM ExtraEmails WHERE Rules = 'true'
I don't know if I'm posting this in the right place - I have a feeling it can't be too difficult but I can't seem to figure it out. I've come across this problem many times and I've never solved it. I would imagine the scenario is commonplace - I have a table of Products with a PK of ProductID, and a table of related images with a FK of ProductID. Each product can have many images, but for my initial display I want to display one product record with one image record. I have a Sequence field in the Images table and I could pick the lowest one. Right and left Joins return too many records - if I have three images for Product 1 then Product 1 is listed three times.
I've gotten around this before using a flag in the Products table, or listing an image in both tables but I'm sure there must be a SQL statement that can get the information that I need.
I've got a TextBox to capture the value of "Name" in Table A.
Ive got a CheckBoxList that displays all the pre-determined values of Table B.
When the user selects an item from the CheckBoxList i want to populate Table C with the value of the selected item from the CheckBoxList and the cooresponding ID associated with the user name for that person's entry.
i have a form view that takes fields from two tables 'Contract' and 'volunteers', however because i used a query builder,i have to input an insert statement. How do i create an insert statement for two tables in one query?
In my database when I fire query it takes 40 secs on 1 crore data, similar when I use join with other table then it take more time. I have taken care non cluster index such thing. But still I want to optimize my query, what other thing I need to take like buffer, disk size etc. I am not sure on this area.
How would you handle an INSERT that gets some values from another table using SELECT, where you wanted some values to come from the source table record and other values to come from a different parameter source like a session value? Is this possible?
if I have three Dropdownlist A, B, C, how can I write a select statement to get data from sql server based on the dropdownlist selected.e.g. if user select dropdownlist A, select * from table where A = dropdownlist A but if user select dropdownlist A and C, then select statment is "select * from table where A = dropdownlist A and B = dropdownlist B or if selected A, B, C.......how can I settle so many choice.
I am having difficulty selecting data from 2 tables that do no share a primary key value. For instance, I have an actual table, a forecast table, and a GLText table. I may have an actual value but not a forecast value but I need them to appear in the same Query (like the query results shown below). I can get all values to appear in each table but have been unsuccessful in getting all values from both tables.