Data Definition Language (DDL) Flashcards
6 cards from real 1Z0-071 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Data Definition Language (DDL) flashcards as text
What is a FOREIGN KEY constraint used for?
Answer: Enforcing referential integrity between two tables
A FOREIGN KEY constraint ensures that values in a column match values in a referenced primary key column of another table.
Which data type stores variable-length character strings up to 4000 bytes in Oracle?
Answer: VARCHAR2
VARCHAR2 stores variable-length character data up to 4000 bytes (or 32767 in extended mode) and is Oracle's recommended string type.
What does a CHECK constraint do?
Answer: Verifies that column values satisfy a specific condition
A CHECK constraint enforces a business rule by validating that column values meet a specified Boolean condition.
Which Oracle statement adds a constraint to an existing table?
Answer: ALTER TABLE table ADD CONSTRAINT ...
ALTER TABLE with ADD CONSTRAINT allows you to add a new constraint to an existing table.
What is the CHAR data type's behavior regarding storage length?
Answer: It pads values with spaces to the defined fixed length
CHAR stores fixed-length character data by right-padding shorter values with spaces to reach the declared length.
Which of the following correctly creates a table with a primary key constraint?
Answer: CREATE TABLE t (id NUMBER PRIMARY KEY, name VARCHAR2(50))
Placing PRIMARY KEY after the column definition creates an inline primary key constraint for that column.