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Oracle Database SQL Language Reference, 11g Release 2 () . 1 Introduction to Oracle SQL Hierarchical Query Pseudocolumns. language (SQL) SELECT statement You may need to restrict the columns that are .. For more information, see Oracle Server SOL Reference. Release 8. about optimization of SQL queries and PL/SQL scripts, however, .. Note: You can automatically generate documentation (HTML, PDF, CHM.

Oracle Sql Queries Pdf

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This tutorial is prepared for beginners to help them understand the basic as well as If you are willing to compile and execute SQL programs with Oracle 11g. Product 6 - 33 1 Retrieving Data Using the SQL SELECT Statement PDF. HTML. Excel. Microsoft Word. Oracle BI Publisher. Oracle Database 11g also. SQL is a database computer language designed for the retrieval and management of data in This tutorial will give you quick start with SQL. .. ORACLE.

SQL clause helps to limit the result set by providing a condition to the query. A clause helps to filter the rows from the entire set of records.

Apart from this SQL Interview Questions Blog, if you want to get trained from professionals on this technology, you can opt for a structured training from edureka!

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Following are the ways in which dynamic SQL can be executed: Write a query with parameters. Using EXEC. What are the various levels of constraints? Constraints are the representation of a column to enforce data entity and consistency.

How can you fetch common records from two tables? For example: 1 Select studentID from student. List some case manipulation functions in SQL? It takes a string as an argument and returns it by converting it into lower case. It takes a string as an argument and returns it by converting it into uppercase.


Some of the available set operators are — Union, Intersect or Minus operators. ALIAS name can be given to any table or a column. For example- Select emp.

Ultimate List of 40 Important SQL Queries

Result from employee emp, department as dept where emp. What are aggregate and scalar functions? Aggregate functions are used to evaluate mathematical calculation and returns a single value.

These calculations are done from the columns in a table. For example- max ,count are calculated with respect to numeric. Scalar functions return a single value based on the input value. Accurate indexing requires that the Primary Key column contain only unique values for this purpose. This guarantees that JOIN statements will maintain integrity and produce valid matches.

We can extend the functionality of the Primary Key so that it automatically increments from a base. For example:. Performance pitfalls can be avoided in many ways. We advise developers to learn SQL server queries to an advanced level for this purpose.


For production purposes, these tips may be crucial to adequate performance. Have a look at this query with a subquery condition:. There are a hundred and one uses for this SQL tool. Suppose you want to archive your yearly Orders table into a larger archive table.

This next example shows how to do it. As an example, this next query fetches a list of customers by the region where there is at least one customer per region:. Substring is probably the most valuable of all built-in functions. Suppose you want to find the substring left of the dots in a web address. UIs in Windows allows doing a lot of tasks. However, UIs are human-friendly but not really computer-friendly: It is type of linear barcodes and mostly widely used for retail applications. There are two Tables; 2.

Query for Creating a View A view is a tailored table that is formed as a result of a query.

What is a DBMS?

Query for Retrieving a View The standard syntax of selecting attributes from a table is applicable to views as well. Query to Display User Tables A user-defined table is a representation of defined information in a table, and they can be used as arguments for procedures or user-defined functions. Query to Display Primary Keys A primary key uniquely identifies all values within a table.

Displaying Foreign Keys Foreign keys link one table to another — they are attributes in one table which refer to the primary key of another table.

Displaying Internal Tables Internal tables are formed as a by-product of a user-action and are usually not accessible. Displaying a List of Procedures A stored procedure is a group of SQL queries that logically form a single unit and perform a particular task. Thus, using the following query you can keep track of them: Swapping the Values of Two Columns in a table In this and subsequent examples, we will use a common company database including several tables which are easily visualized.

We can easily fix this problem with the following SQL statement: Returning a Column of Unique Values Now, suppose that our data entry operator added the same Customers to the Customers table more than once by mistake.

In this example we will return the top 25 from our Customers table: Between Monday and Tuesday Today is Wednesday, and we arrive at work and discover that our new data entry clerk in training has entered all new orders incorrectly on Monday and Tuesday. The Between clause makes the task a breeze: Finding the Intersection of Two Tables Undoubtedly the whole reason that a relational database exists in the first place is to find matching records in two tables!

Here we are going to fetch a list of all records which have matches in the Customers and Orders tables: Here is a quick way to accomplish the task: Making Column Labels More Friendly Aliasing column labels give us the convenience of renaming a column label to something more readable. Always and Everywhere!

In the following example, we will return records from the Orders table where the idea is to get a list of high volume orders for a given item, in this case for customers who ordered more than 50 of the product: Here we can simply add the comment delimiter to deactivate it momentarily: Here, we are going to create the DB as a container for our Customers and Orders tables used in the previous ten examples above: Modifying and Deleting Tables with SQL Imagine that you decide to send a birthday card to your customers to show your appreciation for their business, and so you want to add a birthday field to the Customers table.

The Key to Successful Indexing Accurate indexing requires that the Primary Key column contain only unique values for this purpose. For example: Have a look at this query with a subquery condition:A view is a virtual table which consists of a subset of data contained in a table.

Thus, using the following query you can keep track of them: This query displays the total number of customers by counting each customer ID. How can you select unique records from a table?

Oracle Tutorial

These calculations are done from the columns in a table. BETWEEN operator is used to display rows based on a range of values in a row whereas the IN condition operator is used to check for values contained in a specific set of values.

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