sql

Setting MySQL column names

Say I have these tables: people(id, name), cars(person_id, car) and this query: SELECT c.car FROM people as p, cars as c WHERE c.person_id = p.id AND p.id = 3 I want the c.car column to take its name from the name field in the people table, like this (invalid SQL, just to illustrate): SELECT c.car AS(SELECT name FROM people WHERE...

MySQL Query: Winning Auction Bid

I have a small Bidding system that I'm using for a fantasy auction draft. I'm trying to use the below query to pull up the max bids on each player. However, it's not actually giving me the max bid, it's just giving me the first one entered in to the database. SELECT Bid.id FROM bids AS Bid WHERE Bid.active =1 GROUP BY player_id HAVIN...

How do I specify a default value in a MS Access query?

I have three tables similar to the following: tblInvoices: Number | Date | Customer tblInvDetails: Invoice | Quantity | Rate | Description tblPayments: Invoice | Date | Amount I have created a query called exInvDetails that adds an Amount column to tblInvDetails: SELECT tblInvDetails.*, [tblInvDetails.Quantity]*[tblInvDetails.Rate]*...

How do I write an Oracle SQL query for this tricky question?

Here is the table data with the column name as Ships. +--------------+ Ships | +--------------+ Duke of north | ---------------+ Prince of Wales| ---------------+ Baltic | ---------------+ Replace all characters between the first and the last spaces (excluding these spaces) by symbols of an asterisk (*). The number o...

SQL Like query last match

Hi, I've a database that has a name field. (i.e Firstname M. Lastname or just Firstname Lastname). Trying to filter by lastname. How can I do a query to find the last space? Something like select * from person where name like "% a%" (but the space is the last space) Thanks, Tee ...

MySQL Trigger to prevent INSERT under certain conditions

I want to make a trigger that will prevent the insertion if the birthdate (one of the columns) is in the future. I have this: CREATE TRIGGER foo BEFORE INSERT ON table FOR EACH ROW BEGIN IF NEW.birthdate > CURRENT_DATE() THEN ???mystery??? END IF; END; What goes in the mystery part? ...

Sql join, 2 tables, same fields

I have 2 tables. To simplify: Table 1, users: userId int, userName nvarchar(50) Table 2 , messages: msgId int, msgFrom int, msgTo int... msg1 and msg2, both contain userId. Now I want to get all messages, but instead of the msgFrom I want the user name. I know what to do here: select tabMessages.*, tabUsers.userName ...

What is the best way to store categorical references in SQL tables?

I'm wanting to store a wide array of categorical data in MySQL database tables. Let's say that for instance I want to to information on "widgets" and want to categorize attributes in certain ways, i.e. shape category. For instance, the widgets could be classified as: round, square, triangular, spherical, etc. Should these categories be ...

deleting and reusing a temp table in a stored precedure

Hi I need to SELECT INTO a temp table multiple times with a loop but I just can't do it, because after the table created by SELECT INTO you can't simply drop the table at the end of the loop, because you can't delete a table and create it again in the same batch. so how can I delete a table in a stored procedure and create it again? i...

New help with SQL Server select statement

I need help with select statement in SQL Server / T-SQL My table looks like this: Id (int) QuestionId (int) GenreId (int) QuestionScore (int) I want to select random N rows from this table so that maximum number of same GenreId in the result set is less than X for all GenreId-s except one. For that one GenreId, I need row ...

Find overdrawn accounts in SQL

Hey guys, I have a program that allows me to run queries against a large database. I have two tables that are important right now, Deposits and withdraws. Each contains a history of every user. I need to take each table, add up every deposit and withdraws (per user), then subtract the withdraws from the deposits. I then need to return...

Why are there connections open to my databases?

I have a program that stores user projects as databases. Naturally, the program should allow the user to create and delete the databases as they need to. When the program boots up, it looks for all the databases in a specific SQLServer instance that have the structure the program is expecting. These database are then loaded into a lis...

Observing social web behavior: to log or populate databases?

When considering social web app architecture, is it a better approach to document user social patterns in a database or in logs? I thought for sure that behavior, actions, events would be strictly database stored but I noticed that some of the larger social sites out there also track a lot by logging what happens. Is it good practice to...

JDBC: Does the connection break if i lose reference to the Connection object?

Hi. If i have the following method - public static void C() { Connection con = DriverManager.getConnection(); .... // code return; } and i dont call con.close() , will the connection terminate automatically once the method returns? ...

inserting large number of dates

How can I insert all dates in an year(or more) in a table using sql My dates table has following structure dates(date1 date); Suppose I want to insert dates between "2009-01-01" to "2010-12-31" inclusive. Is there any sql query for the above? ...

The big last_insert_id() problem, again.

Note - this follows my question here: http://stackoverflow.com/questions/2983685/jdbc-does-the-connection-break-if-i-lose-reference-to-the-connection-object Now i have a created a class so i can deal with JDBC easily for the rest of my code - public class Functions { private String DB_SERVER = ""; private String DB_NAME = "tes...

How to prune data set by frequency to conform to paper's description

The MovieLens data set provides a table with columns: userid | movieid | tag | timestamp I have trouble reproducing the way they pruned the MovieLens data set used in: Tag Informed Collaborative Filtering, by Zhen, Li and Young In 4.1 Data Set of the above paper, it writes "For the tagging information, we only keep those tags which ...

How to do bulk update of views?

My database has about 30 views, most of which have a reference to another database on this server (call it DB1). Now, without going into the reasons why, I need to update all those views to DB2, also on the local server. I would hate to have to do this manually on each view. Is there some SQL query I can run that will replace all occu...

ado.net managing connections

Hi, I'm populating a listview with a list of databases on a selected SQL instance, then retrieving a value from each database (It's internal product version, column doesn't always exist) I'm calling the below function to populate the second column of the listview: item.SubItems.Add(DBVersionCheck(serverName, database.Name)) Function D...

Arabic SQL query (on Oracle DB) returns empty result

I have this query (that runs on Oracle 10g database): SELECT ge.*, ge.concept AS glossarypivot FROM s_glossary_entries ge WHERE (ge.glossaryid = '161' OR ge.sourceglossaryid = '161') AND (ge.approved != 0 OR ge.userid = 361) AND concept like 'م%' ORDER BY ge.concept The query must display all words that begin with the arabic le...