Recent questions tagged sql

0 votes

282 views

1 answer

sql server - Good way to use table alias in Update statement?

Using SqlServer, and trying to update rows from within the same table. I want to use a table alias for ... there easier / better ways? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

274 views

1 answer

sql server - SQL query to group by day

I want to list all sales, and group the sum by day. Sales (saleID INT, amount INT, created DATETIME) NOTE: I am using SQL Server 2005. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

313 views

1 answer

sql - Efficient way of getting @@rowcount from a query using row_number

I have an expensive query using the row_number over() functionality in SQL Server 2005. I return only a ... love is @@ROW_NUMBERROWCOUNT :-) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

219 views

1 answer

sql - What is the difference between cube, rollup and groupBy operators?

Question is pretty much in the title. I can't find any detailed documentation regarding the differences. I do ... I often grouped by. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

291 views

1 answer

sql - Relationship of Primary Key and Clustered Index

Can a TABLE have a primary key without a clustered index? And can a TABLE have a clustered index without ... primary key and clustered index? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

224 views

1 answer

sql - SQLite string contains other string query

How do I do this? For example, if my column is "cats,dogs,birds" and I want to get any rows where column contains cats? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

312 views

1 answer

sql server - SQL Script to alter ALL Foreign Keys to add ON DELETE CASCADE

I have a SQL 2005 database with approx 250 tables. I want to temporarily enable ON DELETE CASCADE to all of ... and disables ON DELETE CASCADE? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

185 views

1 answer

sql - MySQL 'create schema' and 'create database' - Is there any difference

Taking a peak into the information_schema database and peaking at the metadata for one of my pet projects, I'm ... as a database). Thanks! See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

266 views

1 answer

sql server - CPU utilization by database?

Is it possible to get a breakdown of CPU utilization by database? I'm ideally looking for a Task Manager type ... to the sqlservr.exe CPU load. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

447 views

1 answer

sql server - How to wait for 2 seconds?

How does one cause a delay in execution for a specified number of seconds? This doesn't do it: WAITFOR DELAY ' ... ; What is the correct format? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

418 views

1 answer

sql - Rails way to reset seed on id field

I have found the "pure SQL" answers to this question. Is there a way, in Rails, to reset the id field for ... the id field reset monthly or so. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

216 views

1 answer

sql - What are the uses for Cross Join?

A cross join performs a cartesian product on the tuples of the two sets. SELECT * FROM Table1 CROSS ... an SQL operation particularly useful? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

287 views

1 answer

sql - Why no many-to-many relationships?

I am learning about databases and SQL for the first time. In the text I'm reading (Oracle 11g: SQL by Joan Casteel) ... to ask why. :-) Thanks! See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

279 views

1 answer

sql server - Can I loop through a table variable in T-SQL?

Is there anyway to loop through a table variable in T-SQL? DECLARE @table1 TABLE ( col1 int ) INSERT into ... Any help is greatly appreciated. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

317 views

1 answer

sql - Postgresql query between date ranges

I am trying to query my postgresql db to return results where a date is in certain month and year. In other ... simpler way to do this? Thanks See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

224 views

1 answer

sql - MySQL GROUP BY two columns

I'm trying to group by multiple columns here - one on each table. It's a scenario where I want to find the ... .id ORDER BY total DESC LIMIT 30 See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

446 views

1 answer

sql server - Read committed Snapshot VS Snapshot Isolation Level

Could some one please help me understand when to use SNAPSHOT isolation level over READ COMMITTED SNAPSHOT in ... for SNAPSHOT isolation. Thanks See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

202 views

1 answer

sql - When to use a View instead of a Table?

When should a View actually be used over an actual Table? What gains should I expect this to produce? Overall, ... like in the first place? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

331 views

1 answer

sql - How can I add a column that doesn't allow nulls in a Postgresql database?

I'm adding a new, "NOT NULL" column to my Postgresql database using the following query (sanitized for the ... the SQL from within Terminal. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

388 views

1 answer

sql - Mysql - How to quit/exit from stored procedure

I have very simple question but i did't get any simple code to exit from SP using Mysql. Can anyone share ... END IF; #proceed the code END; See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

250 views

1 answer

sql - How to select a record and update it, with a single queryset in Django?

How do I run an update and select statements on the same queryset rather than having to do two queries: ... value' where pk_field = some_value See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

297 views

1 answer

sql - How can I get the actual stored procedure line number from an error message?

When I use SQL Server and there's an error, the error message gives a line number that has no correlation to the ... I'm using SQL server 2005. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

302 views

1 answer

sql server - What is the PostgreSQL equivalent for ISNULL()

In MS SQL-Server, I can do: SELECT ISNULL(Field,'Empty') from Table But in PostgreSQL I get a syntax ... I emulate the ISNULL() functionality ? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

177 views

1 answer

sql - Why are foreign keys more used in theory than in practice?

When you study relational theory foreign keys are, of course, mandatory. But in practice, in every place I worked ... it for simplicity's sake. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

517 views

1 answer

sql - WITH (NOLOCK) vs SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED

Could someone give me some guidance on when I should use WITH (NOLOCK) as opposed to SET TRANSACTION ISOLATION ... as opposed to the other? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

368 views

1 answer

sql server - "Prevent saving changes that require the table to be re-created" negative effects

Preamble I was modifying a column in SQL Server 2008 today, changing the datatype from something like currency(18, ... of the source table? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

228 views

1 answer

sql server - Stored procedures/DB schema in source control

Do you guys keep track of stored procedures and database schema in your source control system of choice? When ... than one "Accepted Answer"! See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

405 views

1 answer

sql - Storing DateTime (UTC) vs. storing DateTimeOffset

I usually have an "interceptor" that right before reading/writing from/to the database does DateTime conversion ( ... though. Any thoughts? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

Categories

Just Browsing Browsing

Most popular tags