# Relational operators and logical clauses

Relational operators are modifiers used to establish criteria based on the relationship
 of data to fixed values or other data.

## Description

For example: Relational operators can be used to select a range of zip code values within
 specified upper and lower limits. This can be done using gt and
 lt, as well as the and relational operator to establish
 the selection criteria.

 **Operators**

| Operator | Description |
| --- | --- |
| # or ne | Tests for a not equal condition. |
| or gt or after | Tests for a greater than condition. |
| >= or ge | Tests for a greater than or equal to condition. |
| not or no | Tests a negative condition, reversing a true relation. |
| # or no or not | Not equal to |
| **Clauses**

Logical clauses are used in the selection criteria process.

| Clause | Description |
| --- | --- |
| or or ! | Used between two or more conditions to indicate one or the other must be true. |
| and or & | Used between two or more conditions to indicate that all must be true. |

## Example(s)

**Example 1**

```

 sort entity with state eq "ca"
 list invoices with amount.due not "0"
 list employees with birthday before "1/2/62"
 list employees with age gt "21"
 select entity with no zip
 sort invoices with every amount > "0"
```

 **Example 2**

 This example shows two selection clauses connected with an and modifier,
 which means that both conditions must be evaluated as true for items to be selected for
 processing.

```

 list entity with name "mi]" and with phone "804]"
```

 **Example 3**

 When applying multiple selection criteria clauses against a single attribute value, it is not
 necessary to build a separate selection criteria phase for each. For example:

```

 list customers with state = "ca" or with state = "az" or with state = "va"
```

 This can also be stated as:

```

 list customers with state "ca""az""va"
```

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Source: https://d3codex.com/access/relational-operators-and-logical-clauses/ - part of the D3Codex reference.