Null: Unknown data
Null: any operation that has null is null, except the following:
When set ansi_null of: null = NULL, the result is true.
Set concat_null_yields_null off: NULL is treated as a null string (however, if all the
(i)SET Ansi_nulls {on | OFF}Specifies the SQL-92 compliance behavior of these operators when using the Equals (=) and not equal (<>) comparison operators on null values.NotesThe SQL-92 standard requires a value of equal to (=) or Not equal to (<>)
Today, when I made a cross-Server query for two database servers, I encountered a Problem. "error: 7405 16 heterogeneous query requires that the ansi_nulls and ansi_warnings options be set for the connection. This ensures consistent query semantics.
6.8 Other topicsThis section includes several topics that are not fully suited to any of the sections in the development of this chapter from CLIENT1 to CLIENT5:After using the result set metadata to help verify that the data is appropriate for
--Connect remote SQL or insert data with OPENROWSET--if only temporary access, you can directly use OPENROWSET--Query ExampleSelect * from OpenRowset('SQLOLEDB','SQL Server name';'User name';'Password', database name. dbo. Table name)--Import
From:https://www.cnblogs.com/railgunman/archive/2010/12/25/1916780.htmlConnect remote SQL or insert data with OPENROWSET--if it's just temporary access, you can use OPENROWSET directly--query ExampleSELECT * FROM OPENROWSET (' SQLOLEDB ', ' SQL
SQL Server connections across serversConnect remote SQL or insert data with OPENROWSET--if it's just temporary access, you can use OPENROWSET directly--query ExampleSELECT * FROM OPENROWSET (' SQLOLEDB ', ' SQL Server name '; ' User name '; '
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The data does not say whether you are working on programming or are not going to learn SQL, but virtually every developer will eventually encounter it. You probably don't have to be responsible for creating and maintaining a database, but you should
SQL Authoring Specification
1. Basic SQL Authoring Specification
(1) Direct use of table names in rule 1:sql, no schema as prefix, and cross schema access to create synonym (Data Warehouse, CRM database not applicable).
(2) Rule 2: You must use
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