Candidate key Foreign key Super key Answer:A) Primary key Explanation: Primary key is considered unique in a table. Discuss this Question DBMS Language Multiple-Choice Questions DBMS Constraints Multiple-Choice Questions Advertisement Advertisement
AND & OR operator Advance SQL SQL Constraints SQL function SQL Join SQL Alias SQL SET operation SQL Sequences SQL ViewsIntroduction to Database KeysKeys are very important part of Relational database model. They are used to establish and identify relationships between tables and also to uniquely...
If *PKTableNamecontains a table name,SQLForeignKeysreturns a result set that contains the primary key of the specified table and all the foreign keys that refer to it. The list of foreign keys in other tables does not include foreign keys that point to unique constraints in the specified ta...
ALTER TABLE FALL_GNR_OPS_CODE ADD CONSTRAINT FK_FALL_GNR_OPS_CODE_FALL_GNR_ID FOREIGN KEY (FALL_GNR_ID) REFERENCES FALL_GNR (ID); and -- changeset hermchr:1714384768211-10 dbms:oracle ALTER TABLE FALL DROP PRIMARY KEY DROP INDEX; -- changeset hermchr:1714384768211-11 dbms:oracle CREATE...
all DBMS's do not implement primary keys in the same fashion and because of that, if you wanted to create a cross platform, cross application database application, you could not use primary keys, but instead would need to put a unique constraint on the table in place of the primary k...
Drop all constraints in Database DROP ALL USERS FROM DATABASE Drop and Create Constraint on Very Large Table Drop and recreate table in stored procedure Drop Database Error Msg 3701, Level 11, State 1, Line 1 Drop or Truncate a particular partition. DROP Table - How to force a delete of...
// SELECT * FROM USER_CONSTRAINTS WHERE TABLE_NAME = "tabnam"; --查询是否有主键或者唯一index SET SERVEROUTPUT ON SET LINESIZE 1000 SET FEEDBACK OFF SET LONG 999999 SET PAGESIZE 1000 EXEC DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM,'STORAGE',false);--不显示存储信息 ...
What are primary keys in accounting databases, and what purpose do they serve? Explain the terms primary key, candidate key, and foreign key. Give an example for each. What are the main constraints when a relational database model is being logically designed? Explain your a...
OK, so we have a small parent table (BOWIE_DAD) and a much larger child table (BOWIE_KID) with all the necessary constraints in place. Note we don’t actually have a child row with a FK DAD_ID = 1. So we can potentially delete this row from the BOWIE_DAD table (where ID = 1...
In addition, let's remember that a data model can be a complicated thing. We have all kinds of tables that have primary keys defined that let us identify what they are modeling, and we have relations and constraints and data types and the rest. Ideally, you should be able to look at ...