Transactions and Error-Handling in SQL Server

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Course Description

It is critical to know how to handle errors and manage transactions when programming SQL scripts. Unhandled errors can be very harmful and can cause unexpected situations, such as inconsistent data in your database, or even worse, errors can lead you to make wrong business decisions. In this course, you will learn how to handle errors and discover how to manage transactions in case of an error. Additionally, you will study what happens when two or more people interact at the same time with the same data. You will practice all these concepts using two datasets, one of them based on bank accounts and the other one on an electric bike store.

Transactions and Error Handling in SQL Server

To begin the course, you will learn how to handle errors using the TRY...CATCH construct that provides T-SQL. You will study the anatomy of errors, and you will learn how to use some functions that can give you information about errors.

In this chapter, you will be introduced to the concept of transactions. You will discover how to commit and rollback them. You will finish by learning how to return the number of transactions and their state.

In this chapter, you will deepen your knowledge of handling errors. You will learn how to raise errors using RAISERROR and THROW. Additionally, you will discover how to customize errors.

This chapter defines what concurrency is and how it can affect transactions. You will learn exciting concepts like dirty reads, repeatable reads, and phantom reads. To avoid or allow this reads, you will explore, one by one, the different transaction isolation levels.

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Starting with error handling
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To begin the course, you will learn how to handle errors using the TRY...CATCH construct that provides T-SQL. You will study the anatomy of errors, and you will learn how to use some functions that can give you information about errors.
View Chapter Details Play Chapter Now
Raising, throwing and customizing your errors

In this chapter, you will deepen your knowledge of handling errors. You will learn how to raise errors using RAISERROR and THROW. Additionally, you will discover how to customize errors.
View Chapter Details Play Chapter Now
Transactions in SQL Server

In this chapter, you will be introduced to the concept of transactions. You will discover how to commit and rollback them. You will finish by learning how to return the number of transactions and their state.
View Chapter Details Play Chapter Now
Controlling the concurrency: Transaction isolation levels

This chapter defines what concurrency is and how it can affect transactions. You will learn exciting concepts like dirty reads, repeatable reads, and phantom reads. To avoid or allow this reads, you will explore, one by one, the different transaction isolation levels.
View Chapter Details Play Chapter Now

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Miriam Antona

Software Engineer

Miriam Antona has 10+ years of experience working as a Software Engineer. She is focused on analyzing, designing, and developing software applications for Civil Services and Justice Administration. Miriam loves programming and experimenting with different technologies. She is passionate about databases and enjoys playing with data. She holds a Master of Science Degree in Computer Engineering.

Tracks

Data Engineer with Python

Collaborators

Mona Khalil
Marianna Lamnina

Prerequisites

Intermediate SQL Server

Datasets

Electric bike store dataset and Bank accounts dataset

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Transactions and Error Handling in SQL Server

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Loved by learners at thousands of top companies:

Course Description

Starting with error handling

Welcome!

The TRY...CATCH syntax

Your first error-handling script

Nesting TRY...CATCH constructs

Error anatomy and uncatchable errors

Anatomy review

Correcting compilation errors

Giving information about errors

Error function syntax

Using error functions

Using error functions in a nested TRY...CATCH

Transactions in SQL Server

Transactions

Transaction statements

Correcting a transaction

Rolling back a transaction if there is an error

Choosing when to commit or rollback a transaction

@@TRANCOUNT and savepoints

Modifiers of the @@TRANCOUNT value

Checking @@TRANCOUNT in a TRY...CATCH construct

Using savepoints

XACT_ABORT & XACT_STATE

XACT_ABORT behavior

XACT_ABORT and THROW

Doomed transactions

Raising, throwing and customizing your errors

RAISERROR

RAISERROR syntax

CATCHING the RAISERROR

THROW

THROW with or without parameters

THROW without parameters

Executing a stored procedure that throws an error

THROW with parameters

Customizing error messages in the THROW statement

Ways of customizing error messages

Concatenating the message

FORMATMESSAGE with message string

FORMATMESSAGE with message number

Controlling the concurrency: Transaction isolation levels

Transaction isolation levels

Concurrency phenomena

Using the READ UNCOMMITTED isolation level

READ COMMITTED & REPEATABLE READ

Choosing the correct isolation level

Prevent dirty reads

Preventing non-repeatable reads

SERIALIZABLE isolation level

Prevent phantom reads in a table

Prevent phantom reads just in some rows

SNAPSHOT

Setting READ COMMITTED SNAPSHOT to ON

Comparing WITH (NOLOCK) & READ UNCOMMITTED

Avoid being blocked

Congratulations!