What is a composite primary key field ?

What is a composite primary key field ?
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1 Answer

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Answer : A combination of two or more attributes or keys can collectively identify an NTT set, but they are called composite primary keys.
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Related questions

Why is the composite primary field used ?

Description : Why is the composite primary field used ?

Last Answer : Sometimes it is not possible to form a primary key with a field or to identify a record. In this case, the primary key is formed by combining two or more fields. This type of primary key ... primary key. When composing a primary key with two or more fields, the composite primary key is used.

What is the primary key field ?

Description : What is the primary key field ?

Last Answer : The field in the data table by which the values ​​of a record can be completely distinguished from other records is called the primary key.

Drop Table cannot be used to drop a table referenced by a …………… constraint. A) Local Key B) Primary Key C) Composite Key D) Foreign Key

Description : Drop Table cannot be used to drop a table referenced by a …………… constraint. A) Local Key B) Primary Key C) Composite Key D) Foreign Key

Last Answer : D) Foreign Key

............. is a combination of two of more attributes used as a primary key A) Composite Key B) Alternate Key C) Candidate Key D) Foreign Key

Description : ............. is a combination of two of more attributes used as a primary key A) Composite Key B) Alternate Key C) Candidate Key D) Foreign Key

Last Answer : A) Composite Key

An attribute that uniquely identifies the rows of a table is known as the ....... key. (1) primary (2) candidate (3) composite (4) foreign

Description : An attribute that uniquely identifies the rows of a table is known as the ....... key. (1) primary (2) candidate (3) composite (4) foreign 

Last Answer : primary

Explain when the primary key fields of two data tables need to be the same. ?

Description : Explain when the primary key fields of two data tables need to be the same. ?

Last Answer : Due to the following condition of the relation, the primary key fields of the data tables of the two databases need to be the same to create the relation. 1. The common field must be the primary key ... field size , format etc. should be the same and two tables should be open at the same time.

What is a Foreign Key Field ?

Description : What is a Foreign Key Field ?

Last Answer : Answer : If the primary key field of a file in the database is used as a general field of the data file in the other corner , then that field is called foreign key field.

If an attribute of a composite key is dependent on an attribute of the other composite key, a normalization called ................ is needed. A) DKNF B) BCNF C) Fourth D) Third

Description : If an attribute of a composite key is dependent on an attribute of the other composite key, a normalization called ................ is needed. A) DKNF B) BCNF C) Fourth D) Third

Last Answer : B) BCNF

The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because : (A) Non key attribute V_name is dependent on V_no which is part of composite key (B) Non key attribute V_name is dependent on Qty_sup (C) key attribute Qty_sup is dependent on primary_key unit price (D) key attribute V_ord_no is dependent on primary_key unit price

Description : The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because : (A) Non key attribute V_name is dependent on V_no which is part of composite key (B) ... Qty_sup is dependent on primary_key unit price (D) key attribute V_ord_no is dependent on primary_key unit price

Last Answer : (A) Non key attribute V_name is dependent on V_no which is part of composite key

Specifies the key - explain ?

Description : Specifies the key - explain ?

Last Answer : The tag specifies any direction . The tag sits as a symbol of a specific direction This symbol sits in the angle bracket. The spelling of the tag is to be spelled correctly. The word bold is used to bold the html text. The ... be < /b>. Then the beginning and end of bold will be < b> .

What are the types of key fields and what are they ?

Description : What are the types of key fields and what are they ?

Last Answer : There are generally 3 types of key fields such as a) Primary Key Field b) Composite Primary Key Field c) Foreign Key Field .

Primary key field gives us permission to record duplicate entry. -Technology

Description : Primary key field gives us permission to record duplicate entry. -Technology

Last Answer : False A primary key is a key which identifies records uniquely in a table so it does not give us permission to record duplicate entry.

A primary key field does not allow numbers. -Technology

Description : A primary key field does not allow numbers. -Technology

Last Answer : False Primary key has to identify a unique value which can be present in a table, in a number form also. It means primary key field allow number too.

…………. is a field which is used as a primary key and numbers each record sequentially. -Technology

Description : …………. is a field which is used as a primary key and numbers each record sequentially. -Technology

Last Answer : AutoNumberis a field which is used as a primary key and numbers each record sequentially.

What composite field (composed of E and H fields) is propagated into free space?

Description : What composite field (composed of E and H fields) is propagated into free space?

Last Answer : Radiation field.

What composite field (composed of E and H fields) is found stored in the antenna?

Description : What composite field (composed of E and H fields) is found stored in the antenna?

Last Answer : Induction field.

Field and record are not one - explain. ?

Description : Field and record are not one - explain. ?

Last Answer : Answer : Field and record are not the same as explained below- 1. Field is the column name of the data table. On the other hand, the record is a row of data in all the columns of the data table ... data table is singular. In the case of records, the data in different fields of a row may be similar.

What is a database field ?

Description : What is a database field ?

Last Answer : Database field is the title of the column.

What is a field called ?

Description : What is a field called ?

Last Answer : The field used to identify file and database records is called the key field.

What is a field ?

Description : What is a field ?

Last Answer : File record identification , search , relationships, etc. are done based on a single field . Sai field is called key field.

What is a text field ?

Description : What is a text field ?

Last Answer : , symbols, etc. are used in the field with Text data type , it is called Text ball.

MySQL order by primary key, put one row on top.

Description : MySQL order by primary key, put one row on top.

Last Answer : answer:If you can guarantee that there is only one or zero active records select * from presets order by active asc, id asc

What is a primary key? -Technology

Description : What is a primary key? -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

Define primary key with an example. -Technology

Description : Define primary key with an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

What is primary key? Give an example. -Technology

Description : What is primary key? Give an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

What is a primary key in database? Give an example. -Technology

Description : What is a primary key in database? Give an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

Give one advantage of using primary key. -Technology

Description : Give one advantage of using primary key. -Technology

Last Answer : A primary key uniquely identifies the record in the table.

What is the significance of a primary key? -Technology

Description : What is the significance of a primary key? -Technology

Last Answer : A primary key cannot allow null values and must have a unique index.

What is the utility of primary key in database? Write distinct features of primary keys. -Technology

Description : What is the utility of primary key in database? Write distinct features of primary keys. -Technology

Last Answer : The primary key is used to uniquely identify the record in a database. It can be a column or a set of columns in the table.Main features of the primary key are as follows:1. It must contain a unique value for each record of the table.2. It does not contain null values.

Which of the following fields will not make a suitable primary key? (a) A customer’s account number -Technology

Description : Which of the following fields will not make a suitable primary key? (a) A customer’s account number -Technology

Last Answer : (b) From the given options, the data field can not be set as a primary key because it can’t be fixed for an object.

Primary key is used to …………….. identify the record. -Technology

Description : Primary key is used to …………….. identify the record. -Technology

Last Answer : Primary key is used to uniquelyidentify the record.

The candidate key, which is not used as primary key is called ………….. key. -Technology

Description : The candidate key, which is not used as primary key is called ………….. key. -Technology

Last Answer : The candidate key, which is not used as primary key is calledalternate key.

A primary key value can be NULL. -Technology

Description : A primary key value can be NULL. -Technology

Last Answer : False The primary key of table is used to uniquely identify each and every row in the table. So, its all keys and columns must be defined as NOT NULL.

A foreign key is a primary key in another table. -Technology

Description : A foreign key is a primary key in another table. -Technology

Last Answer : True When a table’s primary key field is added to a related table in order to create the common field which relates two tables, it is called a foreign key in the related table.

What is a primary key? How do we set a primary key? -Technology

Description : What is a primary key? How do we set a primary key? -Technology

Last Answer : Primary key is the key which is used to uniquely identify the records into the table. To set the primary key you have to follow the steps given below:Step 1 Select the field that you want ... 2 Click Primary Key button from the Design tab.orRight click on the selected field and select Primary Key.

Define primary key. How do you set it in MS_Access? -Technology

Description : Define primary key. How do you set it in MS_Access? -Technology

Last Answer : Primary key is the key which is used to uniquely identify the records into the table. To set the primary key you have to follow the steps given below:Step 1 Select the field that you want ... 2 Click Primary Key button from the Design tab.orRight click on the selected field and select Primary Key.

What is a primary key in a table? -Technology

Description : What is a primary key in a table? -Technology

Last Answer : A primary key is a special relational database table column (or combination of columns) designated to uniquely identify each & every table record. It does not contain NULL & duplicate values

Write any one similarity and one difference between primary key and unique Constraint. -Technology

Description : Write any one similarity and one difference between primary key and unique Constraint. -Technology

Last Answer : Similarity: Column with both the constraints will only take unique values.Difference: Column with Primary key constraints will not be able to hold NULL values while Column with Unique constraints will be able to hold NULL values.

Identify the primary key column of Train and Reservation. -Technology

Description : Identify the primary key column of Train and Reservation. -Technology

Last Answer : (i) Train-TrainIdReservation-RefNo(ii) (d) By default, the UNION operator selects all the values.

Write any one similarity and one difference between primary key and unique Constraint -Technology

Description : Write any one similarity and one difference between primary key and unique Constraint -Technology

Last Answer : Similarity: Column with both the constraints will only take unique values.Difference: Column with Primary key constraints will not be able to hold NULL values while Column with Unique constraints will be able to hold NULL values.

The primary advantage of key-to-tape data entry system is A) A large percentage of editing can be performed at the time of data entry B) Key verification is easily performed C) The tape is reusable D) Keying errors can be detected as they occur.

Description : The primary advantage of key-to-tape data entry system is A) A large percentage of editing can be performed at the time of data entry B) Key verification is easily performed C) The tape is reusable D) Keying errors can be detected as they occur.

Last Answer : Answer : C

What is the difference between candidate key, unique key and primary key

Description : What is the difference between candidate key, unique key and primary key

Last Answer : Candidate keys are the columns in the table that could be the primary keys and the primary key is the key that has been selected to identify the rows. Unique key is also useful for identifying the distinct rows in the table.)

What is difference between UNIQUE and PRIMARY KEY constraints?

Description : What is difference between UNIQUE and PRIMARY KEY constraints?

Last Answer : A table can have only one PRIMARY KEY whereas there can be any number of UNIQUE keys. The columns that compose PK are automatically define NOT NULL, whereas a column that compose a UNIQUE is not automatically defined to be mandatory must also specify the column is NOT NULL.

Can a primary key contain more than one columns?

Description : Can a primary key contain more than one columns?

Last Answer : Yes

What is difference between UNIQUE constraint and PRIMARY KEY constraint ?

Description : What is difference between UNIQUE constraint and PRIMARY KEY constraint ?

Last Answer : A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls.

The primary advantage of key-to-tape data entry system is a. A large percentage of editing can be performed at the time of data entry b. Key verification is easily performed c. The tape is reusable d. Keying errors can be detected as they occur

Description : The primary advantage of key-to-tape data entry system is a. A large percentage of editing can be performed at the time of data entry b. Key verification is easily performed c. The tape is reusable d. Keying errors can be detected as they occur

Last Answer : The tape is reusable

What is the difference between unique key and primary key ?

Description : What is the difference between unique key and primary key ?

Last Answer : Unique key can be null; Primary key cannot be null.

What is difference between UNIQUE constraint and PRIMARY KEY constraint?

Description : What is difference between UNIQUE constraint and PRIMARY KEY constraint?

Last Answer : A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can’t contain Nulls. 47.What is Index Cluster? – A Cluster with an index on the Cluster Key 48.When does a Transaction end? – When it is committed or Rollbacked.

The primary advantage of key-to-tape data entry system is a. A large percentage of editing can be performed at the time of data entry b. Key verification is easily performed c. The tape is reusable

Description : The primary advantage of key-to-tape data entry system is a. A large percentage of editing can be performed at the time of data entry b. Key verification is easily performed c. The tape is reusable

Last Answer : c. The tape is reusable

Can you disable and enable Primary key?

Description : Can you disable and enable Primary key?

Last Answer : You can use the ALTER TABLE statement to enable, disable, modify, or drop a constraint. When the database is using a UNIQUE or PRIMARY KEY index to enforce a constraint, and constraints associated ... and any FOREIGN KEY constraints that depend on it: ALTER TABLE dept DISABLE PRIMARY KEY CASCADE;