- A SQL schema can be easily transferred to another user.
- A schema may be shared by several users.
- It enables you to transfer database objects between schemas.
- We gain greater power over the access and protection of database objects.
- A user can be removed without removing the database items that are connected with the user.
- Database objects can be grouped into logical groups using schemas. This is advantageous when several people are collaborating on the same database program and the architecture team needs to keep ...
- Since a schema allows for the logical aggregation of database objects, it can assist us in cases where the database object name is the same but falls into a separate ...
How to retrieve table schema using SQL Server?
- SqlConnection cn = new SqlConnection ("PutYourConnectionStringOverHere");
- SqlDataAdapter da = new SqlDataAdapter ("SELECT * FROM Information_Schema.Tables where Table_Type = 'BASE TABLE'", cn");
- DataTable dt = new DataTable ();
- da.Fill (dt);
How to query information schema?
You could easily use this data to:
- Check what’s on the server and/or in the database
- Check if everything is as expected (e.g. compared to the last time you’ve performed this check)
- Automate processes and build some complex code (e.g. code generators – we’ll talk about this later)
What is schema in SQL with examples?
- Right-click on the specific table name and choose Design option:
- It opens the table designer. ...
- Click on SQL Schema, and it opens the available scheme in the database:
- Select the required schema [Sales], and it gives the warning: Changing the schema of this object will result in all current permissions on this object being dropped
How to view table in SQL Server?
- One row represents one reference
- Scope of rows: all references from view to other entities
- Ordered by schema name, view name
What is the naming convention of SQL Server?
SQL Server supports a three-part naming convention when you refer to the current server. The ISO standard also supports a three-part naming convention. However, the names used in both naming conventions are different. The information schema views are defined in a special schema named INFORMATION_SCHEMA. This schema is contained in each database.
What is visibility of metadata?
The visibility of the metadata in information schema views is limited to securables that a user either owns or on which the user has been granted some permission. For more information, see Metadata Visibility Configuration.
Can information schema views be denied?
Information schema views are defined server-wide and therefore cannot be denied within the context of a user database. To REVOKE or DENY access (SELECT), the master database must be used. By default the public role has SELECT-permission to all information schema views but the content is limited with metadata visibility rules.
Why use a schema in SQL?
Following are some of the main advantages of using a schema in SQL: A SQL schema can be easily transferred to another user. A schema may be shared by several users. It enables you to transfer database objects between schemas. We gain greater power over the access and protection of database objects.
What is SQL Server schema?
SQL Server comes with a certain predefined schema that shares the same names as the built-in database functions and users. It persists primarily for backward compatibility. Here are a few examples of built-in schema:
What is the most important element of SQL?
And one of the essential elements of SQL is a schema.
What is SQL database?
To truly comprehend SQL, it is essential to first understand what a database is. A database is a tool for gathering and storing records. Databases can hold data about individuals, goods, orders, and everything else. Many datasets begin with a word processing application or spreadsheet, but as they grow in size, ...
Who owns the schema?
A database user owns the schema, which has the same name as the database manager. As of SQL Server 2005, a schema is an individual entity (container of objects) distinct from the user who constructs the object. In other words, schemas are similar to separate namespaces or containers used to handle database files.
Can a user be removed without removing the database?
A user can be removed without removing the database items that are connected with the user. Database objects can be grouped into logical groups using schemas. This is advantageous when several people are collaborating on the same database program and the architecture team needs to keep the database tables' credibility.
Get all columns for a table
Query INFORMATION_SCHEMA.COLUMNS to get all columns for the Movies table, sorting by the column name alphabetically:
Get all columns that are part of the primary key for a table
To get all of the columns that are part of the primary key for a specific table, join INFORMATION_SCHEMA.TABLE_CONSTRAINTS and INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE, like this:
Get all tables that contain a specific column
Get all tables that have a column called ‘Id’ by querying INFORMATION_SCHEMA.COLUMNS, like this:
Get all views referencing a specific table
Query INFORMATION_SCHEMA.VIEW_TABLE_USAGE to get all views that reference the ‘Employee’ table, like this:
Get all views that have an INNER JOIN
Query INFORMATION_SCHEMA.VIEWS and look in the VIEW_DEFINITION field for ‘INNER JOIN’, like this:
Get all stored procs that reference a specific table
To look for stored procs that reference a specific table, query INFORMATION_SCHEMA.ROUTINES, like this:
Introduction
Have you ever come across a situation where you need to check first if a table exists? Or have you come across a scenario where you need to check if the table's column exists? Then alter the table by adding your desired column. If you have answered yes to any of these two, you came to the right place.
Benefits
As a database developer or administrator, understanding schema and what tables are in a specific database gives us a good idea what's the underlying structure, which can help you write SQL queries. It also allows us to check if everything is expected or on the database.
Common Usages
Before we start, we'll be using the Northwind database for all our examples. You can download it from here. Now, here are the steps we're going to take. First, get all the databases on our local SQL Server instance, get all the tables, third, let's search for a column, fourth search for constraints, and the last query some views.
Summary
I hope you have enjoyed this article. I know that there are many ways you can use INFORMATION_Schema.
What is the purpose of SQL schema?
Yes, the primary purpose of SQL schema was -is- to facilitate security management: define who [which principals] can access what [which database objects]. This was made particularly easier starting with SQL 2005 when the schema stopped being directly tied to the owner.
What is schema namespace?
The Namespace-like nature of schema can also be put to use in a planned database setting, i.e. one when a single architect designs the database structure in a way which provides distinct type of access, and indeed different behaviors, for distinct user groups. They partition your database to make management easier.