- Introduction To SQL
- SQL Syntax
- SQL SELECT Statement
- SQL SELECT DISTINCT Statement
- SQL WHERE Clause
- SQL AND, OR And NOT Operators
- SQL ORDER BY Keyword
- SQL INSERT INTO Statement
- SQL NULL Values
- SQL UPDATE Statement
- SQL DELETE Statement
- SQL TOP, LIMIT, FETCH FIRST Or ROWNUM Clause
- SQL MIN() And MAX() Functions
- SQL COUNT(), AVG() And SUM() Functions
- SQL LIKE Operator
- SQL Wildcards
- SQL IN Operator
- SQL BETWEEN Operator
- SQL Aliases
- SQL Joins
- SQL INNER JOIN Keyword
- SQL LEFT JOIN Keyword
- SQL RIGHT JOIN Keyword
- SQL FULL OUTER JOIN Keyword
- SQL Self Join
- SQL UNION Operator
- SQL GROUP BY Statement
- SQL HAVING Clause
- SQL EXISTS Operator
- SQL ANY And ALL Operators
- SQL SELECT INTO Statement
- SQL INSERT INTO SELECT Statement
- SQL CASE Statement
- SQL NULL Functions
- SQL Stored Procedures For SQL Server
- SQL Comments
- SQL Operators
- SQL CREATE DATABASE Statement
- SQL DROP DATABASE Statement
- SQL BACKUP DATABASE For SQL Server
- SQL CREATE TABLE Statement
- SQL DROP TABLE Statement
- SQL ALTER TABLE Statement
- SQL Constraints
- SQL NOT NULL Constraint
- SQL UNIQUE Constraint
- SQL PRIMARY KEY Constraint
- SQL FOREIGN KEY Constraint
- ALTER TABLE Orders DROP CONSTRAINT FK_PersonOrder;
- SQL DEFAULT Constraint
- SQL CREATE INDEX Statement
- SQL AUTO INCREMENT Field
- SQL Working With Dates
- SQL Views
- SQL Injection
- SQL Hosting
- SQL Data Types For MySQL, SQL Server, And MS Access
SQL Working With Dates
SQL Dates
The most difficult part when working with dates is to be sure that the format of the date you are trying to insert, matches the format of the date column in the database.
As long as your data contains only the date portion, your queries will work as expected. However, if a time portion is involved, it gets more complicated.
Practice Excercise Practice now
SQL Date Data Types
MySQL comes with the following data types for storing a date or a date/time value in the database:
DATE- format YYYY-MM-DDDATETIME- format: YYYY-MM-DD HH:MI:SSTIMESTAMP- format: YYYY-MM-DD HH:MI:SSYEAR- format YYYY or YY
SQL Server comes with the following data types for storing a date or a date/time value in the database:
DATE- format YYYY-MM-DDDATETIME- format: YYYY-MM-DD HH:MI:SSSMALLDATETIME- format: YYYY-MM-DD HH:MI:SSTIMESTAMP- format: a unique number
Note: The date types are chosen for a column when you create a new table in your database!
Practice Excercise Practice now
SQL Working With Dates
Look at the following table:
Orders Table
| OrderId | ProductName | OrderDate |
|---|---|---|
| 1 | Geitost | 2008-11-11 |
| 2 | Camembert Pierrot | 2008-11-09 |
| 3 | Mozzarella di Giovanni | 2008-11-11 |
| 4 | Mascarpone Fabioli | 2008-10-29 |
Now we want to select the records with an OrderDate of "2008-11-11" from the table above.
We use the following SELECT statement:
The result-set will look like this:
| OrderId | ProductName | OrderDate |
|---|---|---|
| 1 | Geitost | 2008-11-11 |
| 3 | Mozzarella di Giovanni | 2008-11-11 |
Note: Two dates can easily be compared if there is no time component involved!
Now, assume that the "Orders" table looks like this (notice the added time-component in the "OrderDate" column):
| OrderId | ProductName | OrderDate |
|---|---|---|
| 1 | Geitost | 2008-11-11 13:23:44 |
| 2 | Camembert Pierrot | 2008-11-09 15:45:21 |
| 3 | Mozzarella di Giovanni | 2008-11-11 11:12:01 |
| 4 | Mascarpone Fabioli | 2008-10-29 14:56:59 |
If we use the same SELECT statement as above:
we will get no result! This is because the query is looking only for dates with no time portion.
Tip: To keep your queries simple and easy to maintain, do not use time-components in your dates, unless you have to!
Practice Excercise Practice now
Products
Partner
Copyright © RVR Innovations LLP 2024 | All rights reserved - Mytat.co is the venture of RVR Innovations LLP