SQL – Page 1641 – SQL Questions Answer

Divide operation in SQL

SQL BETWEEN for text vs numeric values

between mysql numbers sql varchar

BETWEEN is used in a WHERE clause to select a range of data between two values. If I am correct whether the range’s endpoint are excluded or not is DBMS specific. What I can not understand in the following: If I have a table of values and I do the following query: The query returns as results rows inclu…

Mysql: Update field of most latest record

mysql sql sql-update

I’m trying to update the latest record where name is John (John has multiple records but different ID) but I seem to be in a bind. What’s wrong with my query? UPDATE messages_tbl SET is_unread=1 …

Update only time from my Datetime field in sql

sql sql-server-2008

I have a date 2013-12-14 05:00:00.000 in my table. Now i want to update only time of that date. E.G to 2013-12-14 04:00:00.000 Is there any query to update only time from datetime field? Answer Or this

PostgreSQL – order by an array

aggregate postgresql set-returning-functions sql sql-order-by

I have 2 tables – course that contains id and name of the courses and tagCourse that contains tags for each course. I’d like to write a function that searches courses by given array of tags and returns them ordered by quantity of matching tags. However I don’t know how to write it correctly …

Upgrading a varchar column to enum type in postgresql

database ddl postgresql sql

We have a varchar column in a table, that we need to upgrade to enum type. All the values in the varchar column are valid values in the enumeration. There is no null values in the varchar column. …

Find start and end dates when one field changes

sliding-window sql

I have this data in a table When ever the value in FIELD_D changes it forms a group and I need the min and max dates in that group. The query shoud return The examples that I have seen so far have the data in Field_D being unique. Here the data can repeat as shown, First it is “N” then