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SQL (Structured Query Language) (Constraints : add information about how a…
SQL (Structured Query Language)
designed to manage data stored in relational databases
RDBMS- SQLite Relational Database Management System
Relational DB: organizes information into one or more tables - - - Tables are sometimes referred to as relations
column is a set of data values of a particular type.
A row is a single record in a table
Statements
A statement is text that the database recognizes as a valid command
parameter: a list of columns, data types, or values that are passed to a clause as an argument
clause: clauses perform specific tasks in SQL
Create: creates a new table in the database
Insert: inserts new rows into a table -- values: clause that indicates the data being inserted
Select: used to fetch data from a database
is a special wildcard character that we have been using. It allows you to select every column in a table without having to name each one individually --- always returns a new table called the result set.
Update: is a clause that edits a row in the table
WHERE: clause that indicates which row(s) to update with the new column value
SET: clause that indicates the column to edit
Alter: clause that lets you make the specified changes
ADD COLUMN: clause that lets you add a new column to a table
NULL (special value in SQL) represents missing or unknown data
Delete from: deletes one or more rows from a table
Constraints : add information about how a column can be used are invoked after specifying the data type for a column :fire:
PRIMARY KEY columns can be used to uniquely identify the row
UNIQUE columns have a different value for every row
NOT NULL columns must have a value
DEFAULT columns take an additional argument that will be the assumed value for an inserted row