What?s the difference between PRIMARY KEY and UNIQUE in
MyISAM?
Answers were Sorted based on User's Feedback
Answer / amith
PRIMARY KEY cannot be null, so essentially PRIMARY KEY is
equivalent to UNIQUE NOT NULL
Is This Answer Correct ? | 28 Yes | 8 No |
Answer / niraj kumar
primary key is not accept the null value.primary key is
always autoincrement.unique key is accept the one null
value.it is not a autoincrement.
Is This Answer Correct ? | 4 Yes | 15 No |
Answer / manish
Primary Keys are used in building relationships between
tables in a database. (an index is automatically created on
the primary key). The difference between primary and
ordinary keys is that there can be multiple keys, but only
one primary key.
Is This Answer Correct ? | 7 Yes | 20 No |
How many sql dml commands are supported by 'mysql'?
How to drop an existing view in mysql?
What storage engines are used in MySQL?
change column name and make a unique column so we get no dupes.
Use a regular expression to find records. Use “REGEXP BINARY” to force case-sensitivity. This finds any record beginning with r.
How to calculate the difference between two time values?
What is index length in mysql?
what is the Dynamic management views? where can you use?
What's the difference between mysql and sql server?
How to Change a users password from MySQL prompt. Login as root. Set the password. Update privs.
How can increase the performance of MySQL select query?
3 Answers RV Technologies, Span Systems,
How can we change the name of a column of a table?