Jerod  Mante

Jerod Mante

1601994240

SQL Primary Key Example | Primary Key in SQL Tutorial

SQL primary key is a field in a table that is used for uniquely identifying a row in a table. If the column has a primary key constraint, then it will contain unique values and will not able to contain any NULL values. A primary key length cannot exceed more than 900 bytes.

SQL PRIMARY KEY

SQL PRIMARY KEY constraint uniquely identifies each row in the table. Primary keys must contain UNIQUE values, and cannot contain the NULL values. The table can have only ONE primary key; and in the table, that primary key can consist of the single or multiple columns (fields).

A  table will contain only one primary key, which may consist of single or multiple fields, and when multiple fields are used as a primary key, then it is known as composite keys.

If the table has a primary key defined in any of the fields, then it cannot have two or more records having the same values.

#sql #sql primary key #primary key

What is GEEK

Buddha Community

SQL Primary Key Example | Primary Key in SQL Tutorial
Cayla  Erdman

Cayla Erdman

1594369800

Introduction to Structured Query Language SQL pdf

SQL stands for Structured Query Language. SQL is a scripting language expected to store, control, and inquiry information put away in social databases. The main manifestation of SQL showed up in 1974, when a gathering in IBM built up the principal model of a social database. The primary business social database was discharged by Relational Software later turning out to be Oracle.

Models for SQL exist. In any case, the SQL that can be utilized on every last one of the major RDBMS today is in various flavors. This is because of two reasons:

1. The SQL order standard is genuinely intricate, and it isn’t handy to actualize the whole standard.

2. Every database seller needs an approach to separate its item from others.

Right now, contrasts are noted where fitting.

#programming books #beginning sql pdf #commands sql #download free sql full book pdf #introduction to sql pdf #introduction to sql ppt #introduction to sql #practical sql pdf #sql commands pdf with examples free download #sql commands #sql free bool download #sql guide #sql language #sql pdf #sql ppt #sql programming language #sql tutorial for beginners #sql tutorial pdf #sql #structured query language pdf #structured query language ppt #structured query language

Jerod  Mante

Jerod Mante

1601994240

SQL Primary Key Example | Primary Key in SQL Tutorial

SQL primary key is a field in a table that is used for uniquely identifying a row in a table. If the column has a primary key constraint, then it will contain unique values and will not able to contain any NULL values. A primary key length cannot exceed more than 900 bytes.

SQL PRIMARY KEY

SQL PRIMARY KEY constraint uniquely identifies each row in the table. Primary keys must contain UNIQUE values, and cannot contain the NULL values. The table can have only ONE primary key; and in the table, that primary key can consist of the single or multiple columns (fields).

A  table will contain only one primary key, which may consist of single or multiple fields, and when multiple fields are used as a primary key, then it is known as composite keys.

If the table has a primary key defined in any of the fields, then it cannot have two or more records having the same values.

#sql #sql primary key #primary key

Cayla  Erdman

Cayla Erdman

1596441660

Welcome Back the T-SQL Debugger with SQL Complete – SQL Debugger

When you develop large chunks of T-SQL code with the help of the SQL Server Management Studio tool, it is essential to test the “Live” behavior of your code by making sure that each small piece of code works fine and being able to allocate any error message that may cause a failure within that code.

The easiest way to perform that would be to use the T-SQL debugger feature, which used to be built-in over the SQL Server Management Studio tool. But since the T-SQL debugger feature was removed completely from SQL Server Management Studio 18 and later editions, we need a replacement for that feature. This is because we cannot keep using the old versions of SSMS just to support the T-SQL Debugger feature without “enjoying” the new features and bug fixes that are released in the new SSMS versions.

If you plan to wait for SSMS to bring back the T-SQL Debugger feature, vote in the Put Debugger back into SSMS 18 to ask Microsoft to reintroduce it.

As for me, I searched for an alternative tool for a T-SQL Debugger SSMS built-in feature and found that Devart company rolled out a new T-SQL Debugger feature to version 6.4 of SQL – Complete tool. SQL Complete is an add-in for Visual Studio and SSMS that offers scripts autocompletion capabilities, which help develop and debug your SQL database project.

The SQL Debugger feature of SQL Complete allows you to check the execution of your scripts, procedures, functions, and triggers step by step by adding breakpoints to the lines where you plan to start, suspend, evaluate, step through, and then to continue the execution of your script.

You can download SQL Complete from the dbForge Download page and install it on your machine using a straight-forward installation wizard. The wizard will ask you to specify the installation path for the SQL Complete tool and the versions of SSMS and Visual Studio that you plan to install the SQL Complete on, as an add-in, from the versions that are installed on your machine, as shown below:

Once SQL Complete is fully installed on your machine, the dbForge SQL Complete installation wizard will notify you of whether the installation was completed successfully or the wizard faced any specific issue that you can troubleshoot and fix easily. If there are no issues, the wizard will provide you with an option to open the SSMS tool and start using the SQL Complete tool, as displayed below:

When you open SSMS, you will see a new “Debug” tools menu, under which you can navigate the SQL Debugger feature options. Besides, you will see a list of icons that will be used to control the debug mode of the T-SQL query at the leftmost side of the SSMS tool. If you cannot see the list, you can go to View -> Toolbars -> Debugger to make these icons visible.

During the debugging session, the SQL Debugger icons will be as follows:

The functionality of these icons within the SQL Debugger can be summarized as:

  • Adding Breakpoints to control the execution pause of the T-SQL script at a specific statement allows you to check the debugging information of the T-SQL statements such as the values for the parameters and the variables.
  • Step Into is “navigate” through the script statements one by one, allowing you to check how each statement behaves.
  • Step Over is “execute” a specific stored procedure if you are sure that it contains no error.
  • Step Out is “return” from the stored procedure, function, or trigger to the main debugging window.
  • Continue executing the script until reaching the next breakpoint.
  • Stop Debugging is “terminate” the debugging session.
  • Restart “stop and start” the current debugging session.

#sql server #sql #sql debugger #sql server #sql server stored procedure #ssms #t-sql queries

Jerod  Mante

Jerod Mante

1601990580

SQL Foreign Key Constraint | Foreign Key In SQL Example

SQL foreign key is used to form a link between two tables, which makes it a referencing key.  The foreign key is a constraint, which is a column or a combination of the column which is used to point the  primary key of another table. If the table has the primary key defined on any field(s), then a user cannot have the two records having the same value of that field(s).

SQL Foreign Key Constraint

The primary purpose of the foreign key is that only those values will appear in the columns which are present in the primary key table and a foreign key is a referencing key in one table, the foreign key must match an existing primary key in the referenced table. This enforcement of foreign key is known as referential integrity.

Let’s understand the use of a foreign key with an example.

We are going to create a foreign key with create keyword.

See the following syntax.

Create table table_name(
Column1 datatype,
Column2 datatype,
……..,
Column(n) datatype,
Constraint (constraint name)
FOREIGN KEY [column1, column2…]
REFERENCES [primary_key_table] (column_list_of_primary_key_table) ….);

#sql #sql foreign key #foreign key

Sival Alethea

Sival Alethea

1624316400

SQL Tutorial - Full Database Course for Beginners. DO NOT MISS!!!

In this course, we’ll be looking at database management basics and SQL using the MySQL RDBMS.
⭐️ Contents ⭐
⌨️ (0:00) Introduction
⌨️ (2:36) What is a Database?
⌨️ (23:10) Tables & Keys
⌨️ (43:31) SQL Basics
⌨️ (52:26) MySQL Windows Installation
⌨️ (1:01:59) MySQL Mac Installation
⌨️ (1:15:49) Creating Tables
⌨️ (1:31:05) Inserting Data
⌨️ (1:38:17) Constraints
⌨️ (1:48:11) Update & Delete
⌨️ (1:56:11) Basic Queries
⌨️ (2:08:37) Company Database Intro
⌨️ (2:14:05) Creating Company Database
⌨️ (2:30:27 ) More Basic Queries
⌨️ (2:26:24) Functions
⌨️ (2:45:13) Wildcards
⌨️ (2:53:53) Union
⌨️ (3:01:36) Joins
⌨️ (3:11:49) Nested Queries
⌨️ (3:21:52) On Delete
⌨️ (3:30:05) Triggers
⌨️ (3:42:12) ER Diagrams Intro
⌨️ (3:55:53) Designing an ER Diagram
⌨️ (4:08:34) Converting ER Diagrams to Schemas
📺 The video in this post was made by freeCodeCamp.org
The origin of the article: https://www.youtube.com/watch?v=HXV3zeQKqGY&list=PLWKjhJtqVAblfum5WiQblKPwIbqYXkDoC&index=8
🔥 If you’re a beginner. I believe the article below will be useful to you ☞ What You Should Know Before Investing in Cryptocurrency - For Beginner
⭐ ⭐ ⭐The project is of interest to the community. Join to Get free ‘GEEK coin’ (GEEKCASH coin)!
☞ **-----CLICK HERE-----**⭐ ⭐ ⭐
Thanks for visiting and watching! Please don’t forget to leave a like, comment and share!

#sql #sql tutorial #full database course for beginners #database management basics #sql using the mysql rdbms #sql tutorial - full database course for beginners