////////////SQL Introduction.////////////
Although SQL is an ANSI standard, there are many different versions of the SQL language.
However, to be compliant with the ANSI standard, they all support at least the major commands (such as SELECT, UPDATE, DELETE, INSERT, WHERE) in a similar manner.
Note: Most of the SQL database programs also have their own proprietary extensions in addition to the SQL standard. However, the above posted commands, are quite nice, and come in handy, when working with a WorldOfWarcraft database, for any emulator.<
Another note : Standing the other way of Lua, SQL isn't case sensitive, you should keep that in mind.
////////////The Start Of The Guide////////////
If you know this SQL commands, you're quite far.
& then standing at the side of thisCode:* SELECT - extracts data from a database
* UPDATE - You can update your data with this commands in your database.
* DELETE - You can delete unwished collumns with this command from your database.
* INSERT INTO - You can insert new data in your database, with this command.
So, we'll start with the acctual guide now.Code:* CREATE DATABASE - creates a new database
* CREATE TABLE - Name says it itself.
* ALTER TABLE - Alter, means modify, so you can simply modify a table with this command.
* DROP TABLE - Delete a table with this command.
Your first SQL statement.
The following SQL statement will select all the records in the "Items" table:
Now, that you selected the records, from the Items table, you can also select a certain collumn out of it. We'll still be working in the 'Items' database.Code:SELECT * FROM Items
SQL SELECT Syntax
andCode:SELECT Name (This is the collumn name.)
FROM Items (Table name.)
Now, you want to select the content of the columns named Names, Itemid from the table 'Items.' This can be done this way :Code:SELECT * FROM Items (Table name.)
Next, selecting all collumns, from the table 'Items.' You can do this on a quite simple way. The * in SQL stands for selecting all the collumns.Code:SELECT Names,Itemid(Collumn Names) FROM Items(Table Name)
So :
The next part. Using Distincts. Hence I'm not so good at them yet, I took them from a small guide, posted on a private forum.Code:Select * From Items.
In a table, some of the columns may contain duplicate values. This is not a problem, however, sometimes you will want to list only the different (distinct) values in a table.
The DISTINCT keyword can be used to return only distinct (different) values.
Now we want to select only the distinct values from the column named "City" from the table above.Code:SELECT DISTINCT column_name(s)
FROM table_name
We use the following SELECT statement:
End of the copied part.Code:SELECT DISTINCT City FROM Persons
Now, we'll move on to the next part of my personal guide.
Using the 'Where' command. When you select somthing, with the 'Where' command, you select collumns, with specified vallues.
Example.
We'll use the WHERE command now, to select all collumns in the table 'Items' where it contains a 'Lol' in the name.Code:SELECT Names (Collumn name.
FROM Items (Table name.)
WHERE (Your specification here.)
When you're using 1,2,3,.. numbers, so, you arn't needed to use ' at the begin, and to close it at the end. When you're using text values, you're supposed to open, and close it.Code:SELECT * FROM Items (Selects all collumns from the table items.)
WHERE Name='Lol' (Speaks for itself.)
Code:This is correct:
SELECT * FROM Items WHERE Name='Lol'
This is wrong:
SELECT * FROM Persons WHERE Name=Lol
The AND operator displays a record if both the first condition and the second condition is true.
The OR operator displays a record if either the first condition or the second condition is true.
So :
So no need to apply a second 'Where.' when you're using an AND command.Code:Select * FROM Items
Where Name = 'Lol' (Name, both are collumns.)
AND Id ='4500' (The Itemid.)
Next, the use of the 'OR.' command :
Q:Code:Select * FROM Items
Where Name ='Lol'
OR Name='Lol1'.
A:Yes you can.
On this way :
Congrats, you now can 'look up' collumns, and tables, select them, from the database.Code:SELECT * FROM ITEMS
WHERE Name='Lol'
AND (Itemid='4500' OR Itemid='4501')
////////////INSERTING////////////
The INSERT INTO statement is used to insert a new row in a table.
The value insert of 1 - 2 - 3 has to be the structure of your database.Code:INSERT INTO Items
VALUES (value1, value2, value3,...)
for example.
This will add the data into all collumns, now we're going to add data into specific collumns :Code:INSERT INTO Items
VALUES (4500(Id),'Loller(Name)', '25484(Displayid)')
In this case, your inserted item doesn't have a displayid.Code:INSERT INTO Persons (Id, Name)
VALUES (4500, 'Loller')
Now we're going to update the collumns.
Code:UPDATE Items
SET Names=Lollerlol, Itemid=4500
WHERE Names=Lol AND Itemid=45000
Deleting collumns. <3
Can it be more easyer?Code:DELETE FROM Items
WHERE Itemid=4500
This is it so far. Hope you enjoyed it.Code:DELETE FROM Items
WHERE Name='Lol' AND Name='Loller'
