Chapter 9: Databases Flashcards
Definition of a database
a persistent structured collection of data that allows people to extract information in a way that meets their needs
Definition of a single-table database
a database that contains only one table
Definition of a table
a collection of related records in a database
Definition of a record
a collection of fields that describe one item
Definition of a field
a database table
Definition of a data type
a classification of how data is stored and displayed, and of which operations that can be performed on the stored value
Definition of a primary key
a field in a database that uniquely identifies a record
Definition of Structured Query Language (SQL)
the standard query language for writing scripts to obtain useful information from a relational database
Definition of SQL scripts
a list of SQL commands that perform a given task, often stored in a file so the script can be reused
Definition of SELECT
an SQL command that fetches specified fields (columns) from a table
Definition of FROM
an SQL command that identifies the table to use
Definition of WHERE
an SQL command to include only those records (rows) in a query that match a given condition
Definition of ORDER BY
an SQL command that sorts the results from a query by a given column either alphabetically or numerically
Definition of SUM
an SQL command that returns the sum of all the values in a field (column); used with SELECT
Definition of COUNT
an SQL command that counts the number of records (rows) in which the field (column) matches a specified condition; used with SELECT
