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37 terms

Data Modeling

chapter 7
STUDY
PLAY
False
The ANSI prescribes a standard SQL the current fully apporved version is known as SQL-07
True
The ANSI SQL standards are also accepted by the ISO.
False
SQL is considered difficult to learn; its command set has a vocabulary of more than 300 words.
False
You cannot insert a row containing a null attribute value using SQL.
False
You can select partial table contents by naming the desired fields and by placing restrictions on the rows to be included in the output.
False
Oracle users can use the Access QBE (query by example) query generator.
True
String comparisons are made from left to right.
False
The conditional LIKE must be used in conjuction with wildcard characters.
True
Some RDBMSs, such as Microsoft Access, automatically make the necessary conversions to eliminate case sensitivity.
False
To join tables, simply enumerate the tables in the FROM clause of the SELECT statement. The DBMS will create a Cartesian product of every table in the FROM clause. To get the correct results, you need to select the rows in which the common attribute values do not match.
SQL-2003
The most recent fully approved version of standard SQL prescribed by the ANSI is ___.
CHAR and VARCHAR
The SQL character data formats are ___.
INSERT
The SQL command that lets you insert rows into a table is ___.
COMMIT
The SQL command that lets you insert rows into a table is ___.
SELECT
The SQL command that lets you select attributes from rows in one or more tables is ____.
FORMAT
In Oracle, the ___ command is used to change the display of a column, for example, to place a $ in front of a numeric value.
UPDATE
The SQL command that modifies an attributes values in one or more table's rows is ____.
subquery
A ____ is a query that is embedded or nested inside another query.
ROLLBACK
The ___ command is used to restore the table's contents to their previous values.
DELETE
To delete a row from the PRODUCT table, use the ___ command.
all rows will be deleted
When you issue the DELETE FROM tablename command without specifying a WHERE condition, ____.
alias
An ____ is an alternate name given to a column or table in any SQL statement.
IS NULL
The ____ special operator is used to check whether an attribute value is null.
LIKE
The special operator used to check for similar character strings is ____.
DROP TABLE
A table can be deleted from the database by using the ___ command.
COUNT
The SQL aggregate function that gives the number of rows containing non-null values for a given column is ___.
AVG
The SQL aggregate that gives the average for the specific column is ___.
Schema
A ___ is a logical group of database objects, such as tables and indexes, that are related to each other.
CHAR
U.S. state abbrev. are always 2 characters, so _____ is a logical choice for data type representing a state column.
ORACLE
Date & SYSDATE are special functions that return today's date in MA ACCESS AND ___ respectively.
Reserved Words
are words used by SQL to perform specific functions.
Create INDEX
Using the ___ command, SQL indexes can be created on the basis of any selected attribute.
attribute names
In an INSERT command, you can indicate just that attributes that have required values by listing the ___ inside parentheses after the table name.
wildcard
A ____ character is a symbol that can be used as a general substitute for other characters or commands.
Drop TAble
A table can be deleted from the database by using the ___ command.
Join
A ___ is performed when data is retrieved from more than one table at a time.
recursive
An alias is especially useful when a table must be joined to itself in a ___ query.