📅 最后修改于: 2020-11-29 08:33:22 🧑 作者: Mango
运算符是一个符号，告诉编译器执行特定的数学或逻辑操作。 Tableau具有许多用于创建计算字段和公式的运算符。
以下是可用的运算符的详细信息以及操作的顺序(优先级)。
下表显示了Tableau支持的常规运算符。这些运算符作用于数字，字符和日期数据类型。
| Operator | Description | Example |
|---|---|---|
| +(addition) | Adds two numbers. Concatenates two strings. Adds days to dates. |
7 + 3 Profit + Sales ‘abc’ + ‘def’ = ‘abcdef’ #April 15, 2004# + 15 = #April 30, 2004# |
| –(subtraction) | Subtracts two numbers. Subtracts days from dates. |
-(7+3) = -10 #April 16, 2004# – 15 = #April 1, 2004# |
下表显示了Tableau支持的算术运算运算符。这些运算符仅对数字数据类型起作用。
| Operator | Description | Example |
|---|---|---|
| *(Multiplication) | Numeric multiplication | 23*2 = 46 |
| /(Division) | Numeric division | 45/2 = 22.5 |
| %(modulo) | Reminder of numeric division | 13 % 2 = 1 |
| ^(power) | Raised to the power | 2^3 = 8 |
下表列出的Tableau支持的比较运算符。这些运算符用于表达式中。每个运算符比较两个数字，日期或字符串，并返回一个布尔值(TRUE或FALSE)。但是，布尔值本身无法使用这些运算符进行比较。
| Operator | Description | Example |
|---|---|---|
| = = or = (Equal to) | Compares two numbers or two strings or two dates to be equal. Returns the Boolean value TRUE if they are, else returns false. | ‘Hello’ = ‘Hello’ 5 = 15/ 3 |
| != or <> (Not equal to) | Compares two numbers or two strings or two dates to be unequal. Returns the Boolean value TRUE if they are, else returns false. | ‘Good’ <> ‘Bad’ 18 != 37 / 2 |
| > (Greater than) | Compares two numbers or two strings or two dates where the first argument is greater than second. Returns the boolean value TRUE if it is the case, else returns false. | [Profit] > 20000 [Category] > ‘Q’ [Ship date] > #April 1, 2004# |
| < (Less than) | Compares two numbers or two strings or two dates where the first argument is smaller than second. Returns the boolean value TRUE if it is the case, else returns false. | [Profit] < 20000 [Category] < ‘Q’ [Ship date] < #April 1, 2004# |
下表显示了Tableau支持的逻辑运算符。这些运算符用于结果为布尔值的表达式中，输出为TRUE或FALSE。
| Operator | Description | Example |
|---|---|---|
| AND | If the expressions or Boolean values present on both sides of AND operator is evaluated to be TRUE, then the result is TRUE. Else the result is FALSE. | [Ship Date] > #April 1, 2012# AND [Profit] > 10000 |
| OR | If any one or both of the expressions or Boolean values present on both sides of AND operator is evaluated to be TRUE, then the result is TRUE. Else the result is FALSE. | [Ship Date] > #April 1, 2012# OR [Profit] > 10000 |
| NOT | This operator negates the Boolean value of the expression present after it. | NOT [Ship Date] > #April 1, 2012# |
下表描述了评估运算符的顺序。第一排具有最高优先级。同一行上的运算符具有相同的优先级。如果两个运算符的优先级相同，则会在公式中从左到右对其求值。也可以使用括号。在内括号之前先评估内括号。
| Precedence | Operator |
|---|---|
| 1 | –(negate) |
| 2 | ^(power) |
| 3 | *, /, % |
| 4 | +, – |
| 5 | ==, >, <, >=, <=, != |
| 6 | NOT |
| 7 | AND |
| 8 | OR |