What is the use of SQLite?

SQLite is ACID-compliant and implements most of the SQL standard, using a dynamically and weakly typed SQL syntax that does not guarantee the domain integrity. SQLite is a popular choice as embedded database software for local/client storage in application software such as web browsers.

Keeping this in consideration, is SQLite is free?

SQLite is an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. The code for SQLite is in the public domain and is thus free for use for any purpose, commercial or private. SQLite is a compact library.

How do I install SQLite?

Install SQLite3 on Windows

  • Go to SQLite3 download page, “Precompiled Binaries For Windows” section;
  • Download “sqlite-shell” and “sqlite-dll” archive files;
  • Unpack them in C:WINDOWSsystem32 folder (or any other that is in your PATH);
  • Install the sqlite3 Ruby gem.
  • What is the meaning of SQLite?

    SQLite is an in-process library that implements a self-contained, zero-configuration, serverless, transactional SQL database engine. The source code for SQLite exists in the public domain and is free for both private and commercial purposes.

    IS LEFT JOIN inner or outer?

    INNER JOIN is the default — rows from both tables must match the join condition. Inner join: Only show rows, when has it data from both of the tables. Outer join: (left/right): Show the all result from the left / right table with the paired row(s), if it exists or not.

    What is the difference between inner join and outer join?

    In SQL, a join is used to compare and combine — literally join — and return specific rows of data from two or more tables in a database. An inner join finds and returns matching data from tables, while an outer join finds and returns matching data and some dissimilar data from tables.

    What is the difference between a table and a view?

    A view is a virtual table. A view consists of rows and columns just like a table. The difference between a view and a table is that views are definitions built on top of other tables (or views), and do not hold data themselves. If data is changing in the underlying table, the same change is reflected in the view.

    Why do we use views?

    View can be described as virtual table which derived its data from one or more than one table columns. It is stored in the database. View can be created using tables of same database or different database. It is used to implement the security mechanism in the SQL Server.

    What is the difference between View and materialized view?

    A materialized view is a database object that contains the results of a query. The FROM clause of the query can name tables, views, and other materialized views. Collectively these objects are called master tables (a replication term) or detail tables (a data warehousing term).

    Can you update the data in a SQL view?

    If the view contains joins between multiple tables, you can only insert and update one table in the view, and you can’t delete rows. You can’t directly modify data in views based on union queries. You can’t modify data in views that use GROUP BY or DISTINCT statements. There is no checking of view criteria.

    What is a materialized view and when would it be used?

    A view uses a query to pull data from the underlying tables. A materialized view is a table on disk that contains the result set of a query. Materialized views are primarily used to increase application performance when it isn’t feasible or desirable to use a standard view with indexes applied to it.

    What is the use of materialized view in Oracle?

    Materialized Views in Oracle. A materialized view, or snapshot as they were previously known, is a table segment whose contents are periodically refreshed based on a query, either against a local or remote table.

    Can we create an index on a view?

    Views make queries faster to write, but they don’t improve the underlying query performance. Once we create an indexed view, every time we modify data in the underlying tables then not only must SQL Server maintain the index entries on those tables, but also the index entries on the view.

    What is a clustered index?

    A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages. Instead, the leaf nodes contain index rows.”

    What is an indexed view?

    The first index created on a view must be a unique clustered index. Creating a unique clustered index on a view improves query performance because the view is stored in the database in the same way a table with a clustered index is stored. The query optimizer may use indexed views to speed up the query execution.

    What is clustered index in SQL?

    An index contains keys built from one or more columns in the table or view. These keys are stored in a structure (B-tree) that enables SQL Server to find the row or rows associated with the key values quickly and efficiently. A table or view can contain the following types of indexes: Clustered.

    What is schema binding?

    SCHEMABINDING is an option that is available for objects in T-SQL which contain user defined code. Examples include, stored procedures, indexes, and functions. Straight from MSDN, SCHEMABINDING… Specifies that the schema is bound to the database objects that it references.

    What are the triggers in SQL?

    A trigger is a special kind of stored procedure that automatically executes when an event occurs in the database server. DML triggers execute when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT , UPDATE , or DELETE statements on a table or view.

    What is a view in a database?

    A database view is a searchable object in a database that is defined by a query. Though a view doesn’t store data, some refer to a views as “virtual tables,” you can query a view like you can a table. A view can combine data from two or more table, using joins, and also just contain a subset of information.

    How views are stored in database?

    View is a simple SQL statement that is stored in database schema (INFORMATION_SCHEMA.Views). So when ever we call the view the SQL statement gets executed and return the rows from main physical table. You can also tell the view as a Logical table that store the defination (the sql statement) but not the result.

    What is a trigger in a database?

    A trigger is a special type of stored procedure that automatically executes when an event occurs in the database server. DML triggers execute when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT, UPDATE, or DELETE statements on a table or view.

    What is the main purpose of triggers in database?

    A database trigger is special stored procedure that is run when specific actions occur within a database. Most triggers are defined to run when changes are made to a table’s data. Triggers can be defined to run instead of or after DML (Data Manipulation Language) actions such as INSERT, UPDATE, and DELETE.

    What is a trigger and its types?

    Types of triggers. A trigger defines a set of actions that are performed in response to an insert, update, or delete operation on a specified table. When such an SQL operation is executed, the trigger is said to have been activated. Triggers are optional and are defined using the CREATE TRIGGER statement.

    How do I install sqlite?

    Install SQLite3 on Windows

  • Go to SQLite3 download page, “Precompiled Binaries For Windows” section;
  • Download “sqlite-shell” and “sqlite-dll” archive files;
  • Unpack them in C:WINDOWSsystem32 folder (or any other that is in your PATH);
  • Install the sqlite3 Ruby gem.