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Query by Example (QBE) is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL. It is the first graphical query language, using visual tables where the user would enter commands, example elements and conditions.
Access, the successor to ENGLISH, is an English -like query language used in the Pick operating system . The original name ENGLISH is something of a misnomer, as PICK's flexible dictionary structure meant that file and attribute names could be given aliases in any natural language. For instance the command SORT could be given the alias TRIEZ ...
VBA can also be included in queries. Microsoft Access offers parameterized queries. These queries and Access tables can be referenced from other programs like VB6 and .NET through DAO or ADO. From Microsoft Access, VBA can reference parameterized stored procedures via ADO.
Structured Query Language ( SQL) ( pronounced S-Q-L; historically "sequel") [4] [5] is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling structured data, i.e., data incorporating relations among entities and variables.
Referential integrity is a property of data stating that all its references are valid. In the context of relational databases, it requires that if a value of one attribute (column) of a relation (table) references a value of another attribute (either in the same or a different relation), then the referenced value must exist. [1]
SET ROWCOUNT {rows} select * from {table} where {unique_key} > {last_val} order by {unique_key} SET ROWCOUNT 0. SET ROWCOUNT {rows} select * from ( select * from {table} where {unique_key} < {first_val} order by {unique_key} DESC ) a order by {unique_key} SET ROWCOUNT 0. Sybase, SQL Server 2000.
A query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. This is a specific case of the relational model concept of access plans.
Overview. WHERE is an SQL reserved word. The WHERE clause is used in conjunction with SQL DML statements, and takes the following general form: SQL-DML-Statement FROM table_name WHERE predicate. all rows for which the predicate in the WHERE clause is True are affected (or returned) by the SQL DML statement or query.
A join clause in the Structured Query Language combines columns from one or more tables into a new table. The operation corresponds to a join operation in relational algebra . Informally, a join stitches two tables and puts on the same row records with matching fields : INNER , LEFT OUTER , RIGHT OUTER , FULL OUTER and CROSS .
In Microsoft Access, the asterisk sign * matches zero or more characters, the question mark? matches a single character, the number sign # matches a single digit (0–9), and square brackets can be used for sets or ranges of characters to match.