DECLARE语句用于在存储过程或函数中声明变量,并为其分配数据类型。我们还提供了一个示例代码来演示DECLARE语句的使用方法。希望通过本文,读者可以更好地理解和运用DECLARE语句来存储和处理数据。 参考资料: [MySQL DECLARE statement]( [MySQL Data Types](
When handling thesql_variant data type, SQL Server supports implicit conversions of objects with other data types to thesql_variant type. However, SQL Server does not support implicit conversions fromsql_variant data to an object with another data type. declare@var_intsql_variantdeclare@var_bitsq...
--declare variable and set to $1.99DECLARE@MyMoneymoney=1.99SELECT@MyMoneyASMyMoney Smallmoney Data Type Smallmoney represents a monetary value Range of values: – 214,748.3648 to 214,748.3647 Storage size: 4 Bytes --declare variable and set to $1.99DECLARE@MySmallMoneysmallmoney=1.99SELECT@My...
DECLARE@timetime(5)SET@time='2009-01-01 10:00:10.122'SELECT@timeastime_value Copy What About Timestamp? Thetimestampdata type has nothing to do with dates. This datatype is also known as "rowversion". The timestamp column is automatically updated whenever the row is update...
Unlike SQL, PL/SQL lets you declare variables, to which the following topics apply: CHAR and VARCHAR2 Variables LONG and LONG RAW Variables ROWID and UROWID Variables 3.1.1Different Maximum Sizes The SQL data types listed inTable 3-1have different maximum sizes in PL/SQL and SQL. ...
DECLARE @notastring INT; SET @notastring = '1'; SELECT @notastring + ' is not a string.' AS Result 在此例中,SELECT 语句会引发以下错误:输出 复制 Msg 245, Level 16, State 1, Line 3 Conversion failed when converting the varchar value ' is not a string.' to data type int. 为了计...
Make any reasonable assumptions about data types, and be sure to declare primary and foreign keys. Solution 代码语言:javascript 复制 create table person (driver_id varchar(50), name varchar(50), address varchar(50), primary key (driver_id)); create table car (license_plate varchar(50), ...
使用Visual Basic 中构造函数的规范构造 DataType 对象 此代码示例演示如何使用构造函数创建基于不同 SQL Server 数据类型的数据类型实例。 备注 UserDefinedType、UserDefinedDataType和 XML 类型全都需要名称值以标识对象。 VBNET 'Declare a DataType object variable and define the data type in the constructor....
AnInt32value that specifies the precision for numeric SQL Server data types. scale 类型:System.Int32 AnInt32value that specifies the scale for numeric SQL Server data types. 示例 Visual Basic 复制 'Declare and create a DataType object variable. Dim dt As DataType dt = New DataType(SqlData...
EXEC SQL END DECLARE SECTION; /* Extract some characters from the middle */ /* of the argument and return them */ *arg_loc = arg1; EXEC SQL VALUES SUBSTR(arg_loc, 10, 20) INTO :res_loc; *result = res_loc; Structured Types ...