relation between two tables factUsinggroup byto get the max_date, then an inner join to get ...
Most PostgreSQL commands implicitly use locks to control concurrent access to data in tables. You can also use these locks explicitly in your application code with theLOCKcommand. Many lock modes aren't compatible with each other, and they can block transactions when they're trying to access the...
if a name is present in both tables its quantity should be added..is it possible to obtain the above result .there is no relation between the tablesThanks in advance#598993 29 Mar 2011 22:56 Nagendra Points: 3 Try the following declare @test3 Table ( col1 varchar(30), col2 int ) ...
In ADO.Net you can easily set up this relation between two tables in a DataSet using a DataRelation. All you need is two tables where one is considered the parent and one and is considered the child and a name for their relation. Once this is setup, you can easily get the child rows...
Relation is sometimes used to refer to a table in a relational database but is more commonly used to describe the relationships that can be created between those tables in a relational database. Advertisements In relational databases, a relationship exists between two tables when one of them ha...
SQL allows duplicates in relations as well as in query results. To force the elimination of duplicates, insert the keyword distinct after select. select distinctdept_namefrominstructor The keywordallspecifies that duplicates should not be removed. ...
The MBR (also known as the bounding box) for a two-dimensional geometry is the smallest rectangle which holds all points in the geometry, and so encloses the area between its greatest extents in both coordinate directions. In other words, it is the rectangle bounded by the points (min(x)...
You select a value that describes the subtle relationship between two tables. For example, the valueCompositionmeans that the child record cannot meaningfully exist without being related to a specific parent record. The record for the fourth floor in theFloortable cannot exist without referencing a ...
The OpenGIS specification defines the following functions that test the relationship between two geometry values g1 and g2. The MySQL implementation uses minimum bounding rectangles, so these functions return the same result as the corresponding MBR-based functions described earlier in this section. ...
tables_in_string to_a to_ary to_sql touch_all uniq_value(<= v5.0.0.1) update update!(>= v7.0.0) update_all update_counters _update_record(<= v5.1.7) values values_for_create(<= v5.2.3) values_for_queries(>= v7.0.0)