CS352 Lecture - Commercial Query Languages: SQL, QBE last
... (3) It is also possible for any system that has the db2 JDBC driver installed to access the database via JDBC - for example, this is the case with my laptop. The JDBC driver is written in Java, and hence runs on any system that runs Java - it does not have to be running db2. For a JDBC connection, ...
... (3) It is also possible for any system that has the db2 JDBC driver installed to access the database via JDBC - for example, this is the case with my laptop. The JDBC driver is written in Java, and hence runs on any system that runs Java - it does not have to be running db2. For a JDBC connection, ...
Introduction to the Relational Model and SQL
... query optimizer that derives an efficient query evaluation plan (i.e., an imperative program that evaluates the query) from this declarative specification. In earlier models, programmers had to explicitly think about the use of indexes and many more details. ...
... query optimizer that derives an efficient query evaluation plan (i.e., an imperative program that evaluates the query) from this declarative specification. In earlier models, programmers had to explicitly think about the use of indexes and many more details. ...
Template file - Goldsmiths, University of London
... query and modify a database; you can now implement your own database (even though, it probably will be far from a good design) ...
... query and modify a database; you can now implement your own database (even though, it probably will be far from a good design) ...
Statement
... Calling next() the first time makes the cursor points to the first row (If there is one). next() returns false if there is no more row in the result set. Otherwise it returns true. ...
... Calling next() the first time makes the cursor points to the first row (If there is one). next() returns false if there is no more row in the result set. Otherwise it returns true. ...
Chapter 1 Overview of Database Concepts
... • Display multiple columns of a table • Use a column alias to clarify the contents of a particular column • Perform basic arithmetic operations in the SELECT clause ...
... • Display multiple columns of a table • Use a column alias to clarify the contents of a particular column • Perform basic arithmetic operations in the SELECT clause ...
Pclec04 - Monash University
... In SQL-92 these are the date/time data types There is a very complete specification for Date, Time, and Timestamp data types There are rules for converting from numeric and character strings into these temporal types, and there is also a time zone table schema used for conversions (it hasn’t been im ...
... In SQL-92 these are the date/time data types There is a very complete specification for Date, Time, and Timestamp data types There are rules for converting from numeric and character strings into these temporal types, and there is also a time zone table schema used for conversions (it hasn’t been im ...
Fundamentals of Database Systems
... functions are not updateable Views defined on multiple tables using joins are generally not updateable WITH CHECK OPTION: must be added to the definition of a view if the view is to be updated to allow check for updatability and to plan for an execution strategy ...
... functions are not updateable Views defined on multiple tables using joins are generally not updateable WITH CHECK OPTION: must be added to the definition of a view if the view is to be updated to allow check for updatability and to plan for an execution strategy ...
host language
... Relational data model doesn't match well with data model of conventional programming languages (e.g., data structure mismatch) No pointers, loops or branches in SQL No convenient input and output (e.g., formatting) ...
... Relational data model doesn't match well with data model of conventional programming languages (e.g., data structure mismatch) No pointers, loops or branches in SQL No convenient input and output (e.g., formatting) ...
AdvancedQueries
... fulfill the qualification in WHERE clause, project on fields that are needed (in SELECT or GROUP BY) Partition the remaining tuples into groups by the value of attributes in grouping-list For each group, the group qualification is then applied selecting only those groups that fulfill the qualifi ...
... fulfill the qualification in WHERE clause, project on fields that are needed (in SELECT or GROUP BY) Partition the remaining tuples into groups by the value of attributes in grouping-list For each group, the group qualification is then applied selecting only those groups that fulfill the qualifi ...
CSc-340 04a
... SQL:1999 permits the use of functions and procedures written in other languages such as C or C++ Declaring external language procedures and functions create procedure dept_count_proc(in dept_name varchar(20), out count integer) language C external name ’ /usr/avi/bin/dept_count_proc’ create function ...
... SQL:1999 permits the use of functions and procedures written in other languages such as C or C++ Declaring external language procedures and functions create procedure dept_count_proc(in dept_name varchar(20), out count integer) language C external name ’ /usr/avi/bin/dept_count_proc’ create function ...
1. Introduction to SQL Tuning
... to determine the fastest access path. However, we can influence the decision of the optimizer when needed to alter the access path. This is the process of tuning the statement. Application logic can be tuned. For example, a 3GL such as C or COBOL can incorporate array processing. PL/SQL can use bulk ...
... to determine the fastest access path. However, we can influence the decision of the optimizer when needed to alter the access path. This is the process of tuning the statement. Application logic can be tuned. For example, a 3GL such as C or COBOL can incorporate array processing. PL/SQL can use bulk ...
table - Staffordshire University
... Tables may be joined together – this is very powerful but can get complex Database systems which allow join relationships are known as Relational Databases (see RDSD) To build, use and maintain joins between tables, it is often easiest to use tools built into database programs ...
... Tables may be joined together – this is very powerful but can get complex Database systems which allow join relationships are known as Relational Databases (see RDSD) To build, use and maintain joins between tables, it is often easiest to use tools built into database programs ...
Document
... – SQLCODE (long, is negative if an error has occurred) – SQLSTATE (char[6], predefined codes for common errors) ...
... – SQLCODE (long, is negative if an error has occurred) – SQLSTATE (char[6], predefined codes for common errors) ...
SQL Server Procedures
... configuration of SQL server. The hardened environment does not necessarily have a predictable set of configuration options to consider. The remainder of this document addresses some of the ways SQL security has been locked down and some ways to configure it so that MessageStats functions properly. ...
... configuration of SQL server. The hardened environment does not necessarily have a predictable set of configuration options to consider. The remainder of this document addresses some of the ways SQL security has been locked down and some ways to configure it so that MessageStats functions properly. ...
create table - NCNU Moodle 課程
... • Generic versions of SQL commands for every example presented in this chapter • In most cases, commands in Access are identical to the generic versions • For those commands that differ, both the generic version and the Access version are included ...
... • Generic versions of SQL commands for every example presented in this chapter • In most cases, commands in Access are identical to the generic versions • For those commands that differ, both the generic version and the Access version are included ...
Chapter 3
... For those commands that differ, both the generic version and the Access version are included ...
... For those commands that differ, both the generic version and the Access version are included ...
Chapter 3
... • Generic versions of SQL commands for every example presented in this chapter • In most cases, commands in Access are identical to the generic versions • For those commands that differ, both the generic version and the Access version are included ...
... • Generic versions of SQL commands for every example presented in this chapter • In most cases, commands in Access are identical to the generic versions • For those commands that differ, both the generic version and the Access version are included ...
SQL is a standard computer language for accessing and
... accessing and manipulating database systems. SQL statements are used to retrieve and update data in a database. SQL works with database programs like MS Access, DB2, Informix, MS SQL Server, Oracle, Sybase, etc. Unfortunately, there are many different versions of the SQL language, but to be in compl ...
... accessing and manipulating database systems. SQL statements are used to retrieve and update data in a database. SQL works with database programs like MS Access, DB2, Informix, MS SQL Server, Oracle, Sybase, etc. Unfortunately, there are many different versions of the SQL language, but to be in compl ...
SAS and ORACLE PL/SQL: Partners or Competitors'
... instantiated using the %TYPE declaration which refers to the data type stored on the database – the advantage being that if the column definition changes the code will use the new definition the next time it executes. Control structures allow you to code for complex conditions ordinarily not accessi ...
... instantiated using the %TYPE declaration which refers to the data type stored on the database – the advantage being that if the column definition changes the code will use the new definition the next time it executes. Control structures allow you to code for complex conditions ordinarily not accessi ...
Simple version control
... Stored procedures. No problem. Simply replace it. In alphabetical order. Views. Table-valued functions. Not so easy. Must preserve specific order of creation. Simply name script file with number prefixes. ...
... Stored procedures. No problem. Simply replace it. In alphabetical order. Views. Table-valued functions. Not so easy. Must preserve specific order of creation. Simply name script file with number prefixes. ...
Slide 1
... • The original SQL as specified for SYSTEM R also had a CONTAINS comparison operator, which is used in conjunction with nested correlated queries – This operator was dropped from the language, possibly because of the difficulty in implementing it efficiently – Most implementations of SQL do not have ...
... • The original SQL as specified for SYSTEM R also had a CONTAINS comparison operator, which is used in conjunction with nested correlated queries – This operator was dropped from the language, possibly because of the difficulty in implementing it efficiently – Most implementations of SQL do not have ...
Null (SQL)
Null is a special marker used in Structured Query Language (SQL) to indicate that a data value does not exist in the database. Introduced by the creator of the relational database model, E. F. Codd, SQL Null serves to fulfill the requirement that all true relational database management systems (RDBMS) support a representation of ""missing information and inapplicable information"". Codd also introduced the use of the lowercase Greek omega (ω) symbol to represent Null in database theory. NULL is also an SQL reserved keyword used to identify the Null special marker.For people new to the subject, a good way to remember what null means is to remember that in terms of information, ""lack of a value"" is not the same thing as ""a value of zero""; similarly, ""lack of an answer"" is not the same thing as ""an answer of no"". For example, consider the question ""How many books does Juan own?"" The answer may be ""zero"" (we know that he owns none) or ""null"" (we do not know how many he owns, or doesn't own). In a database table, the column reporting this answer would start out with a value of null, and it would not be updated with ""zero"" until we have ascertained that Juan owns no books.SQL null is a state (unknown) and not a value. This usage is quite different from most programming languages, where null means not assigned to a particular instance.