GoConqr hat ein neues Design! Sag uns, wie es dir gefällt.

Kostenlos registrieren

Karteikarten

SQL

James Norman OCR A level Computer Science A level Englisch 12 Karten

Karten in diesem Stapel (12)

  1. 1Structured Query Language (SQL)Declarative language
    Used for querying and modifying database tables
  2. 2SELECT FROM WHERE SELECT FROM WHEREExtract specific fields (or every field if * is used) with specific properties from the specified table(s)
  3. 3Conditions for SELECT= :: Equal to
    > :: Greater than
    < :: Less than
    != :: Not equal to
    >= :: Greater than or equal to
    <= :: Less than or equal to
    IN :: Value within a given set
    LIKE :: Similar to
    BETWEEN AND :: Takes one of a range of values
    IS NULL :: Empty field
    AND, OR, NOT :: Logical operators
  4. 4JOIN ONAnother way of combining selections from multiple tables
  5. 5CREATE TABLE [IF NOT EXISTS] ( ... )Creates a new table with the specified fields
    IF NOT EXISTS is optional, and will only create a new table if a table with the provided name doesn't already exist within the database
  6. 6Datatypes for CREATE TABLE1. CHAR(n) - Character string of fixed length n
    2. VARCHAR(n) - Variable-length character string, max length n
    3. BOOLEAN - takes TRUE of FALSE in capitals here
    4. INTEGER, INT
    5. FLOAT
    6. DATE - Day, month, year
    7. TIME - Hour, minute, second
    8. CURRENCY - Formats to region
  7. 7ALTER TABLE [ADD] [DROP COLUMN] [MODIFY COLUMN]Changes structure of an existing table
    ADD - adds a new column
    DROP COLUMN - deletes column
    MODIFY COLUMN - edits an existing column
  8. 8Defining keys in SQLEnd of CREATE TABLE statement
    Add FOREIGN KEY REFERENCES for foreign keys
    Use PRIMARY KEY (, , ..., ) for creating primary keys with 'n' parts
  9. 9INSERT INTO (, ...) VALUES (, ...)Adds a new record to the database
  10. 10UPDATE SET = WHERE =Updates a record in the database
  11. 11DELETE FROM WHEREDeletes records satisfying a certain condition
  12. 12CRUD methodsPrepared statements for security
    Create - Create new tables or records in the database
    Read - Get values from the database
    Update - Alter tables or records in the database
    Delete - Remove tables or records from the database

Informationen

Beschreibung
A level OCR A level Computer Science (Topic 4 - Exchanging Data) Karteikarten am SQL, erstellt von James Norman am 28/01/2020.
Erstellt von
James Norman
Aufrufe
0
Bewertung

Feedback

Worum geht es?

Wie gefällt dir das neue Design?

Dein Eindruck