Overview of Transactions¶ Let us go through the details related to Transactions.* We typically perform operations such as COMMIT and ROLLBACK via the applications. COMMIT will persist the changes in the database. ROLLBACK will revert the uncommitted changes in the database. We typically rollback the uncommitted changes in a transaction if there is any exception …
Updating Data¶ Let us see how we can update data in the table. Typical syntax UPDATE <table_name> SET col1 = val1, col2 = val2 WHERE <condition> If WHERE condition is not specified all rows in the table will be updated. For now we will see basic examples for update. One need to have good knowledge …
Inserting Data¶ Let us see how to insert the data into the table. We need to use INSERT clause to insert the data. Here is the sample syntax. INSERT INTO <table_name> (col1, col2, col3) VALUES (val1, val2, val3) If we don’t pass columns after table name then we need to specify values for all the …
Creating Table¶ Before getting into action with respect to basic DML and queries or CRUD operations, we need to prepare tables.At this time we have not covered DDL yet. All database operations related to managing tables come under DDL. For now, let’s just create the table by copy pasting below CREATE TABLE statement. We will …
CRUD Operations¶ Let us get an overview of CRUD Operations. They are nothing but DML and queries to read the data while performing database operations. CRUD is widely used from application development perspective. C – CREATE (INSERT) R – READ (READ) U – UPDATE (UPDATE) D – DELETE (DELETE) As part of the application development …
Database Operations – Overview¶ Let us get an overview of Database Operations we typically perform on regular basis. They are broadly categorized into the following: DDL – Data Definition Language CREATE/ALTER/DROP Tables CREATE/ALTER/DROP Indexes Add constraints to tables CREATE/ALTER/DROP Views CREATE/ALTER/DROP Sequences DML – Data Manipulation Language Inserting new data into the table Updating existing …
