让你提前认识软件开发(30):数据库脚本中的空行与空格
第2部分 数据库SQL语言 数据库脚本中的空行与空格 在数据库脚本中,空行与空格起着锦上添花的作用。恰当地使用它们,可以提高代码的规范性及可阅读性,进而提升数据库的编程效率。 1. 空行 空行起着分隔脚本段落的作用,适当的空行可以使脚本的布局更加的清
第2部分 数据库SQL语言
数据库脚本中的空行与空格
在数据库脚本中,空行与空格起着“锦上添花”的作用。恰当地使用它们,可以提高代码的规范性及可阅读性,进而提升数据库的编程效率。
1. 空行
空行起着分隔脚本段落的作用,适当的空行可以使脚本的布局更加的清晰。空行的作用有以下几个:
(1) 用于分隔两个数据表的创建脚本
示例:
create table tb_example1
(
[表内容实现代码]
)
go
-- 空行
create table tb_example2
(
[表内容实现代码]
)
go
(2) 用于分割两个存储过程的创建脚本
示例:
-- pr_example1
[存储过程pr_example1实现代码]
-- 空行
-- pr_example2
[存储过程pr_example2实现代码]
(3) 用于分割不同逻辑脚本代码块
示例:
[脚本代码块1]
-- 空行
[脚本代码块2]
2. 空格
空行起着分隔字符的作用,适当的空格可以使脚本的布局更加整洁清晰。有关空格的使用要注意以下几点:
(1) 多元运算符和它们的操作数之间至少需要一个空格
示例:
select @v_id = 1 -- 注意:“=”前后有空格
select @v_name = ‘hello’ -- 注意:“=”前后有空格
select @v_num = @v_num + 1 -- 注意:“=”和“+”前后有空格
(2) 据库关键字之后要留空格
if、while等关键字之后应留一个空格之后再跟左括号“(”,以突出关键字。
示例:
if (@tableindex=1) -- 注意:“if”之后有一个空格
begin
[执行语句]
end
(3) 创建表、存储过程、触发器、函数等的时候,表名、存储过程名、触发器名和函数名等之后不要留空格
表名、存储过程名、触发器名和函数名之后紧跟左括号“(”,以与关键字区别开来。
(4) 建议不要使用TAB键,而使用空格进行缩进,缩进为4个空格
这是为了消除不同编辑器对TAB键处理的差异,防止用不同的编辑器打开同一份代码时出现排版不工整的情况。
在实际的软件项目中,恰当地使用空行与空格,可使得代码更加的美观。这对提高工作效率是很有好处的。
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