Apoorv Kumar and Apul
... of each of the entity sets participating in R, and let the descriptive attributes (if any) of R be b1, b2, . . . , bn. We represent this relationship set by a table called R with one column for each attribute of the set: ...
... of each of the entity sets participating in R, and let the descriptive attributes (if any) of R be b1, b2, . . . , bn. We represent this relationship set by a table called R with one column for each attribute of the set: ...
slides
... Queries on the GCUTours database return the results virtually instantaneously With a small database, the performance of a query is not an issue However, when there are many thousands of rows in the database tables, it can take a lot more time to extract the rows you want If query performance is poor ...
... Queries on the GCUTours database return the results virtually instantaneously With a small database, the performance of a query is not an issue However, when there are many thousands of rows in the database tables, it can take a lot more time to extract the rows you want If query performance is poor ...
Database
... It seems that it would be simple enough to list the order # 1004 by changing the above query. Query: How many different items were ordered on order number 1004, and what are they? SELECT ORDER_ID, COUNT (*) FROM ORDER_LINE_T WHERE ORDER_ID = 1004; But in Oracle, here is the result: Result: ERROR at ...
... It seems that it would be simple enough to list the order # 1004 by changing the above query. Query: How many different items were ordered on order number 1004, and what are they? SELECT ORDER_ID, COUNT (*) FROM ORDER_LINE_T WHERE ORDER_ID = 1004; But in Oracle, here is the result: Result: ERROR at ...
A primary key
... existing constraints before adding new constraints ALTER TABLE Employee DROP CONSTRAINT EmpFK; ...
... existing constraints before adding new constraints ALTER TABLE Employee DROP CONSTRAINT EmpFK; ...
Document
... CREATE TABLE emp_department_1 AS SELECT fname, minit, lname, bdate FROM employee WHERE dno = 1 ; create table high_pay_emp as select * from employee where salary > 50000 ...
... CREATE TABLE emp_department_1 AS SELECT fname, minit, lname, bdate FROM employee WHERE dno = 1 ; create table high_pay_emp as select * from employee where salary > 50000 ...
No Slide Title
... The SELECT and FROM statements are always required WHERE is only needed if conditions are to be applied to the result ...
... The SELECT and FROM statements are always required WHERE is only needed if conditions are to be applied to the result ...
PowerPoint
... • Supports Oracle 8 and MySQL 3.23 • Most queries that can be expressed in both these dialects can be expressed by users via the API – without breaking the paradigm of a flat namespace ...
... • Supports Oracle 8 and MySQL 3.23 • Most queries that can be expressed in both these dialects can be expressed by users via the API – without breaking the paradigm of a flat namespace ...
SELECT first_name, last_name, salary FROM employees a WHERE
... • Tables contain rows of data with a column for each datum. • Each column is of a specific data type • Columns without data are NULL • Each table has a primary key – a column that has unique values that identify rows • Columns may have foreign key references to a column in another table. The value i ...
... • Tables contain rows of data with a column for each datum. • Each column is of a specific data type • Columns without data are NULL • Each table has a primary key – a column that has unique values that identify rows • Columns may have foreign key references to a column in another table. The value i ...
Slide 1
... • Select employeeID, count(customerID) from Orders where shipCity = ‘ny’ having count <100 • List the number of customers with orders shipped to NY for each employee but only if the count is greater than 100. • “where” constrains what goes into group • ‘having” constrains what goes in result ...
... • Select employeeID, count(customerID) from Orders where shipCity = ‘ny’ having count <100 • List the number of customers with orders shipped to NY for each employee but only if the count is greater than 100. • “where” constrains what goes into group • ‘having” constrains what goes in result ...
Notes on SQL (Structured Query Language): LIS 384K.11, Database
... Note: If you specify WITH CHECK OPTION, then any update operations (DELETE, INSERT, UPDATE) to the table(s) in the select_statement will be checked for compliance with the conditions of the select_statement before they are permitted to take effect in the table(s). Hence, you should use this option o ...
... Note: If you specify WITH CHECK OPTION, then any update operations (DELETE, INSERT, UPDATE) to the table(s) in the select_statement will be checked for compliance with the conditions of the select_statement before they are permitted to take effect in the table(s). Hence, you should use this option o ...
table1.column
... You use an outer join to also see rows that do not usually meet the join condition. Outer join operator is the plus sign (+). ...
... You use an outer join to also see rows that do not usually meet the join condition. Outer join operator is the plus sign (+). ...
09 - SQL basics, including scripts and CGI
... Tables = a collection of rows and columns, called 'fields'. Field = named columns in a table that have a specific type Relational database = databases with tables that contain related fields ...
... Tables = a collection of rows and columns, called 'fields'. Field = named columns in a table that have a specific type Relational database = databases with tables that contain related fields ...
Representing Entity Sets as Tables
... table EM Table EM has attributes corresponding to the primary key of E and an attribute corresponding to multivalued attribute M E.g. Multivalued attribute dependent-names of employee is represented by a table employee-dependent-names( employee-id, dname) Each value of the multivalued attribut ...
... table EM Table EM has attributes corresponding to the primary key of E and an attribute corresponding to multivalued attribute M E.g. Multivalued attribute dependent-names of employee is represented by a table employee-dependent-names( employee-id, dname) Each value of the multivalued attribut ...
6232B_03
... Permissions can be granted at the schema level to apply to all objects within a schema ...
... Permissions can be granted at the schema level to apply to all objects within a schema ...
Ring Charts
... possibly a waste of time and space. They may contain only one or two essential fields that that could be placed on another table, allowing the query to run with fewer joins. A table may be present whose content is not employed in combination with others in the database and could be stored independen ...
... possibly a waste of time and space. They may contain only one or two essential fields that that could be placed on another table, allowing the query to run with fewer joins. A table may be present whose content is not employed in combination with others in the database and could be stored independen ...
15372547-SQL - Cisco Support Community
... surrogate primary key, usually in those situations similar to the above where candidate keys are multi-column. The awkwardness of a multicolumn candidate key becomes apparent as soon as you define a foreign key on it. ...
... surrogate primary key, usually in those situations similar to the above where candidate keys are multi-column. The awkwardness of a multicolumn candidate key becomes apparent as soon as you define a foreign key on it. ...
SQL Tutorial Basics of the SELECT Statement
... characters. NOT LIKE displays rows not fitting the given description. Other possiblities of using LIKE, or any of these discussed conditionals, are available, though it depends on what DBMS you are using; as usual, consult a manual or your system manager or administrator for the available features o ...
... characters. NOT LIKE displays rows not fitting the given description. Other possiblities of using LIKE, or any of these discussed conditionals, are available, though it depends on what DBMS you are using; as usual, consult a manual or your system manager or administrator for the available features o ...
Supporting Join Queries
... A “latest snapshot” query that joins the latest values of keys. “return all CEs that Steve is allowed to use” (Resource Broker) This query would involve joining tuples from CE tables, VO tables and denied users tables Probably interesting! ...
... A “latest snapshot” query that joins the latest values of keys. “return all CEs that Steve is allowed to use” (Resource Broker) This query would involve joining tuples from CE tables, VO tables and denied users tables Probably interesting! ...
Altering tables
... The following statement is prohibited because it removes the birth_date column which is included in the view. The with schemabinding clause protects from such operations. ALTER TABLE Student DROP COLUMN birth_date The following statement is valid: ALTER TABLE Student DROP COLUMN email ...
... The following statement is prohibited because it removes the birth_date column which is included in the view. The with schemabinding clause protects from such operations. ALTER TABLE Student DROP COLUMN birth_date The following statement is valid: ALTER TABLE Student DROP COLUMN email ...
Document
... – A relational operation that causes two or more tables with a common domain to be combined into a single table or view ...
... – A relational operation that causes two or more tables with a common domain to be combined into a single table or view ...
Models of Databases and Database Design
... Relationships and Keys A relationship is an association between two or more tables. Relationships are expressed in the data values of the primary and foreign keys. A primary key is a column or columns in a table whose values uniquely identify each row in a table. A foreign key is a column or columns ...
... Relationships and Keys A relationship is an association between two or more tables. Relationships are expressed in the data values of the primary and foreign keys. A primary key is a column or columns in a table whose values uniquely identify each row in a table. A foreign key is a column or columns ...
Database Design: DBS CB, 2nd Edition
... CREATE VIEW Synergy AS SELECT Likes.drinker, Likes.beer, Sells.bar FROM Likes, Sells, Frequents WHERE Likes.drinker = Frequents.drinker AND Likes.beer = Sells.beer AND Sells.bar = Frequents.bar; Natural join of Likes, Sells, and Frequents ...
... CREATE VIEW Synergy AS SELECT Likes.drinker, Likes.beer, Sells.bar FROM Likes, Sells, Frequents WHERE Likes.drinker = Frequents.drinker AND Likes.beer = Sells.beer AND Sells.bar = Frequents.bar; Natural join of Likes, Sells, and Frequents ...