define coalesce

Objective In the previous section we talked about data types and a few things to note in the string, and we went on to talk about string lines as well as other content and interspersed content, short content, in-depth explanation. (Refer to the

DECODE ()Introduction to the Decode () function:Main role: Translation of query results into other values (that is, in other forms of expression, the following examples);How to use:Select decode (ColumnName, value 1, translation value 1, value 2,

Http://www.ibm.com/developerworks/cn/data/library/techarticles/dm-0604changhp/ The powerful functions provided by DB2 allow developers to create highly efficient and stable stored procedures. But for beginnersProgramIt is not easy. This article

:) Off-TopicLong time no writing essays recently always for other things to worry about reverse telecommuting emotional problems and mood is low and so bad mood is not easy to get sick yesterday burned a day well all over the family is my all want

1 Introduction to null valuesNULL is a unique data type in the database. If a column in a record is NULL, the value of this column is unknown and uncertain. Since it is unknown, there are several possibilities. Therefore, NULL is not a definite

Summary:RDD: Elastic distributed DataSet, is a special set of ' support multiple sources ' have fault tolerant mechanism ' can be cached ' support parallel operation, an RDD represents a dataset in a partitionThere are two operators of

Wiki. openbravo. comwikiERP2.50Developers _ GuideConceptsDBPL-SQL_code_rules_to_write_Oracle_and_Postgresql_codeProcedureLanguagerulesOpenbravoERPsupportsOracleandPostgreSQLdatabaseengines.Thisisasetofrecommendat Http://wiki.openbravo.com/wiki/ERP/2.

Advanced queries are most frequently used in databases and are also the most widely used. For more information about how to learn sqlserver, see. Advanced queries are most frequently used in databases and are also the most widely used. For more

Ø basic common Query-- SelectSelect * from student;-- All query allSelect all sex from student;-- Duplicate distinct FilteringSelect distinct sex from student;-- Count statisticsSelect count (*) from student;Select count (sex) from student;Select

http://blog.csdn.net/binger819623/article/details/5280267First, the concept of zoningSecond, why use zoning? AdvantagesIii. type of partition Four, sub-partitionV. Modification of partitions (additions, deletions, decomposition, merging)Vi.