Learn how to use the TRUNCATE command to clear a table from all of its rows and the differences between TRUNCATE and DELETE.
- [Instructor] Previously in our chapter,…we learned about Oracle DDL commands.…DDL commands, or data definition language command,…allows us to create new database objects…such as creating new tables,…but they also allow us to modify the structure of…existing database objects such as…adding new columns to our tables.…So let's see an example DDL command…where we will add a new column to our table.…I can accomplish that by typing, alter table,…the table name, test_table1, in my case,…add, and then inside brackets,…the column name and column data types.…
So for example col3 and a data type…of number with a precision of 10.…So this command, alter table, test_table1,…which is the name of the table, add,…and then inside brackets the column name, col3, in our case,…and the column data type, number with a precision of 10.…So this command will add col3 to our table.…Let's run the command, we see that the database…notified us that the table has been indeed altered,…and let's select data from our table.…
So select * from test_table1…
Note: This training course is appropriate for beginning database developers with no prior experience with SQL or Oracle.
- Using Oracle SQL*Developer, the free development environment
- Selecting data from tables
- Filtering data
- Using functions to manipulate data
- Joining data from tables
- Creating tables
- Updating values
- Truncating data
- Grouping and ordering result sets
- Working with primary keys
- Checking constraints
Skill Level Beginner
Database Foundations: Core Conceptswith Adam Wilbert2h 14m Beginner
Database Foundations: Administrationwith Adam Wilbert1h 14m Beginner
Oracle 12c Database: Administrationwith David Yahalom3h 58m Beginner
1. Introduction to SQL
2. Preparing the Course Environment
Downloading the course VM2m 16s
3. Using Oracle SQL Developer
4. Basic SELECT Queries
5. String, Number, and Date Functions
6. Joining Table Data
7. Manipulating Data
8. Grouping Data
9. Advanced Topics
Next steps1m 33s
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