User porton

3 answers

12 votes

9k views

2 bookmarks

Implementing a one to zero or one relationship in SQL

database-design foreign-key

Dec 13 '11 at 15:55

1 answers

6 votes

432 views

1 bookmarks

Are two indexes needed?

Jun 11 '12 at 14:22

4 answers

4 votes

3k views

Two ways to define may-have-a (1..0-1) relationship

mysql database-design foreign-key unique-constraint subtypes

Nov 3 '15 at 16:28

3 answers

4 votes

11k views

Assigning empty string to INT NULL field in MySQL

mysql datatypes type-conversion

Jul 16 '18 at 18:54

1 answers

3 votes

13k views

Get week/month data

mysql

Dec 5 '12 at 9:34

1 answers

3 votes

302 views

Sequential joining of tables in order

mysql order-by

Mar 6 '13 at 19:46

2 answers

3 votes

249 views

Finding rows for a specified date range

mysql datetime

Jul 14 '13 at 15:07

1 answers

2 votes

162 views

One table or several tables?

database-design

Apr 16 '12 at 15:39

1 answers

2 votes

2k views

Difference data between adjacent rows

mysql select cursors

Aug 31 '14 at 21:50

2 answers

1 votes

1k views

#1093 - You can't specify target table 'R' for update in FROM clause

mysql subquery errors

Sep 1 '14 at 13:03

2 answers

1 votes

72 views

Is LIMIT processed before or after retrieving data?

mysql performance optimization query-performance

Jun 7 '15 at 12:22

1 answers

1 votes

110 views

Extract data for all groups in a single SELECT statement

mysql order-by

Oct 4 '13 at 14:25

2 answers

1 votes

262 views

Should I create a multi-column UNIQUE index?

mysql index myisam unique-constraint

Jun 23 '14 at 16:04

1 answers

1 votes

713 views

1 bookmarks

Why does it use temporary? (MySQL)

mysql performance index index-tuning explain

Jun 4 '17 at 16:40

1 answers

1 votes

188 views

A MySQL EXPLAIN number of rows discrepancy

mysql performance explain performance-tuning

Jun 5 '17 at 11:52

2 answers

1 votes

2k views

A low cardinality column index and SELECT

mysql index cardinality-estimates

Dec 18 '18 at 17:02

1 answers

1 votes

67 views

Adding an index without a lag (PostgreSQL)

postgresql performance index postgresql-performance

Jul 24 '20 at 19:08

1 answers

1 votes

8k views

Getting the first day of week

mysql date-format

Dec 19 '12 at 13:47

1 answers

1 votes

38 views

Stroring a type of an entry

normalization database-design

Nov 1 '12 at 9:31

0 answers

1 votes

50 views

A separate table or ENUM?

foreign-key database-design

May 13 '13 at 12:28

2 answers

1 votes

37 views

A query for a latest version of data

mysql stored-procedures view datetime

Apr 23 '13 at 16:33

1 answers

1 votes

41 views

PostgreSQL chooses a wrong order of Hash Join

postgresql query-performance join execution-plan postgresql-13

Aug 6 at 16:45

1 answers

0 votes

121 views

Sorting by a field in child table

mysql join order-by sorting

Nov 11 '13 at 15:01

1 answers

0 votes

38 views

Which of tables key to reference?

mysql database-design foreign-key primary-key

Apr 25 '13 at 14:43

1 answers

0 votes

85 views

best relationship for this design?

mysql foreign-key mysql-workbench

Apr 25 '13 at 16:28

1 answers

0 votes

343 views

1 bookmarks

How to represent it with UNIQUE indexes and foreign keys?

foreign-key database-design

Jul 4 '13 at 18:32

1 answers

0 votes

80 views

Several variants of a string in tables

database-design

Oct 23 '12 at 20:20

1 answers

0 votes

76 views

Two dichotomy views of a table, and means to express this as a stored procudure?

mysql stored-procedures view

Mar 5 '13 at 12:59

0 answers

0 votes

19 views

Force PostgreSQL not to think beyond what EXPLAIN says

postgresql query-performance execution-plan explain

Aug 6 at 16:06

2 answers

0 votes

4k views

"Cannot drop index 'unique_token_data': needed in a foreign key constraint" in MySQL without a foreign key

mysql foreign-key mysql-5.7 errors unique-constraint

Jun 3 '19 at 0:14

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