Logical contsructs consists of other logical constructs, formulas and values, which are connected through logical operators. For example, comparisons with equal, unequal and so on.

Operator | Description | Example | Descripltion |
---|---|---|---|

AND | Means that the values at both sides of the operator must be TRUE, otherwise this operator returns FALSE. The execution priority is (in SQL) bigger than OR, but smaller than NOT. | preis > 10 AND preis < 100 | Price is bigger than 10 and smaller then 100. |

NOT | Logical negation, makes from FALSE an TRUE value and vice versa. Biggest execution priority of all logical operators. | NOT preis=0 | Price is not zero. |

OR | Means that at least one of the values at both sides of the operator must be TRUE, otherwise this operator returns FALSE. This operator is executed after NOT and AND. | preis > 10 AND preis < 100 OR preis > 1000 | Price must be bigger than 10 and smaller than 100 or bigger than 1000. |

= | Is TRUE when the values at both sides of the operator are equal. The execution priority is bigger than these of NOT, AND and OR. | preis = 10 | Price is equal to 10. |

> | Is TRUE when the value at the left side of the operator is greater than the value at the right side. The execution priority is bigger than these of NOT, AND and OR. | preis > 0 | Price is bigger than 0. |

>= | Is TRUE when the value at the left side of the operator is greater or equal to the value at the right side. The execution priority is bigger than these of NOT, AND and OR. | preis >= 300 | Price is bigger than or equal to 300. |

< | Is TRUE when the value at the left side of the operator is smaller than the value at the right side. The execution priority is bigger than these of NOT, AND and OR. | preis < 300 | Price is smaller than 300. |

<= | Is TRUE when the value at the left side of the operator is smaller ot equal to the value at the right side. The execution priority is bigger than these of NOT, AND and OR. | preis <= 300 | Price is smaller than or equal to 300 is. |

<> | Is TRUE when the value at the left side of the operator is not equal to the value at the right side. The execution priority is bigger than these of NOT, AND and OR. | preis <> 0 | Price is not equal to 0. |