I am getting empty row on following sql SELECT * FROM flyers WHERE fId=’6′ AND ‘userId’=’400’ MySQL returned an empty result set (i.e. zero rows). (Query took 0.0004 sec) But when i use SELECT …
Tag: database
One table with many field or two table with fewer fields?
My question is simple, currently, I have a database with an “User” table which contains important information about each users (email, username, password), an “Identity” table which contain the first name, last name, birthday… of an user, and a “Medias” table which cu…
Which is faster in sql: searching for a table, or searching for data in table? [closed]
Say there are 1,000 tables in a database, and each table has 1,000 rows. When I search for single table from these 1,000 tables, is the search time same as that required to search for data within one …
SQL: Select only one row of table with same value
Im a bit new to sql and for my project I need to do some Database sorting and filtering: Let’s assume my database looks like this: What should I do to only have the last column with the same email te be returned: Thanks in advance! Answer SQL Query: Hope this solves your problem. Thanks.
How to decide which fields must be indexed in a database table
Explanation I have a table which does not have a primary key (or not even a composite key). The table is for storing the time slots (opening hours and food delivery available hours) of the food shops. Let’s call the table “business_hours” and the main fields are as below. shop_id day (0 R…
MySQL rows checksum
Is it possible to select entire row in a table and get sort of checksum? I am looking for a way to tell my code to update data only if at least one record has been changed. From perspective of data …
Postgresql delete multiple rows from multiple tables
Consider 2 or more tables: I wish to delete all users and their orders that match first name ‘Sam’. In mysql, I usually do left join. In this example userid is unknown to us. What is the correct format of the query? Answer http://www.postgresql.org/docs/current/static/sql-delete.html You can also …
Join query in Access 2013
Currently have a single table with large amount of data in access, due to the size I couldn’t easily work with it in Excel any more. I’m partially there on a query to pull data from this table. 7 …
RETURNING rows using unnest()?
I’m trying to return a set of rows after doing UPDATE. Something like this. but postgres complains, rightly so: set-valued function called in context that cannot accept a set How am I supposed to go about implementing this? That is, RETURNING a set of rows from SELECTed array after UPDATE? I’m awa…
where does woocommerce store orders?
I’m looking in the sql db and I can see something that resembles orders inside wp_posts . However, I would expect them to be inside the tables beginning with wp_woocommerce. Can anyone shed some light on this phenomenon? Cheers Answer In woocommerce orders are modelled as a custom post type so they are …