How to fetch records from multiple tables in a database ?

[kALAMATHI]

I am reading this forum since along time and taking benefits of it , but I have never posted any of the queries before, this for the for the first time that I am posting a query on the forum , I am actually a student and I am pursuing a course of Data base administrator , it is quite easy as far as the simple queries are concerned about the queries about the queries which are used to fetch the records from multiple tables , it would be a great help if anyone provides any sort of help.

[Vandam]

Yes you an definitely do that, it can be done with the help of the concept of joins, I will explain you with an example . Suppose you are maintaining multiple tables and you have a table named as Employee and and another table named as Employee details, the first table contains employee's official information and the second table contains about his salary details, so if you want to fetch the record of the employees whose salary is more than any particular amount say 15000 per month then you will have to use this concept.

[Vandam]

Yes for that you will have to use the SQL join concept for that purpose . If you think that you are new to queries , joins can be a intimidating theory. There are many dissimilar sorts of joins and apparently small information obtainable that give details and compare them. But after you grasp a few fundamental concepts, you will not find it that much difficult to do it practically.

[Steyn]

While the definitions and explanations in this thread seems to be simple and does not include complex logic, so it would be better for you to begin with easier concept . JOIN is a query clause that can be utilized with the statements such as SELECT, UPDATE, and DELETE . You can also called them as data query statements to at the same time influence rows from multiple tables.

[Dwarner]

Joined tables should each comprise at least one column in both tables that hold similar data. For instance, if you want to connect a Employee table and a Salary table, they both must hold a general element, such as a Employee ID column, to provide as a key on which the data can be coordinated. Tables can be joined on more than one fields so long as the fields have the ability to provide similar information.