Default values can be NULL, or they can be a value that matches thedata typeof the column (number, text, date, for example). Let’s see how to implement this in different databases and see some examples. Oracle
Array data type in SQL server Array's IN SQL SERVER? ASCII values for extended characters Assign empty string '' if datetime is null Assign EXEC output to Variable Assigning NULL value to column name using Case Statement of where is SQL SERVER 2008 atomic if not exists() and insert or up...
11.6 Data Type Default Values Data type specifications can have explicit or implicit default values. Explicit Default Handling ADEFAULTvalueclause in a data type specification explicitly indicates a default value for a column. Examples: CREATETABLEt1(iINTDEFAULT-1,cVARCHAR(10)DEFAULT'',priceDOUBLE(16...
SQL კოპირება CREATE TABLE dbo.doc_exz (column_a INT, column_b INT); -- Allows nulls. GO INSERT INTO dbo.doc_exz (column_a) VALUES (7); GO ALTER TABLE dbo.doc_exz ADD CONSTRAINT DF_Doc_Exz_Column_B DEFAULT 50 FOR column_b; GO CREATE...
My SQL / SQL Server / Oracle / MS Access: CREATETABLEPersons ( ID intNOTNULL, LastName varchar(255)NOTNULL, FirstName varchar(255), Age int, City varchar(255)DEFAULT'Sandnes' ); TheDEFAULTconstraint can also be used to insert system values, by using functions likeGETDATE(): ...
13.6 Data Type Default Values Data type specifications can have explicit or implicit default values. ADEFAULTvalueclause in a data type specification explicitly indicates a default value for a column. Examples: CREATETABLEt1(iINTDEFAULT-1,cVARCHAR(10)DEFAULT'',priceDOUBLE(16,2)DEFAULT0.00); ...
A default value can be a literal character string that you define or one of the following SQL constant expressions: USER CURRENT TODAY DBSERVERNAME Not all columns require default values, but as you work with your data model, you might discover instances where the use of a default value ...
SQL Copy CREATE TABLE dbo.doc_exz ( column_a INT, column_b INT ); -- Allows nulls. GO INSERT INTO dbo.doc_exz (column_a) VALUES (7); GO ALTER TABLE dbo.doc_exz ADD CONSTRAINT DF_Doc_Exz_Column_B DEFAULT 50 FOR column_b; GO Use CREATE TABLE You can cre...
INSERT INTO student(NAME) VALUES('李四'); INSERT INTO student(NAME) VALUES('王五'); INSERT INTO teacher VALUES(3,'张三',10) 1. 2. 3. 4. 6、外键 作用:约束两种表的数据。 示例: -- 部门表(主表) CREATE TABLE dept( id INT PRIMARY KEY, ...
For bulk import in SQL Server, both bcp and BULK INSERT load default values to replace null values. For both, you can choose to retain null values.