168 lines
2.7 KiB
PHP
168 lines
2.7 KiB
PHP
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<li>
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NOT, !
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Logical NOT. Evaluates to 1 if the
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operand is 0, to 0 if
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the operand is non-zero, and NOT NULL
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returns NULL.
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<b class='title'>DQL condition :** NOT 10
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-> 0
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<b class='title'>DQL condition :** NOT 0
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-> 1
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<b class='title'>DQL condition :** NOT NULL
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-> NULL
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<b class='title'>DQL condition :** ! (1+1)
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-> 0
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<b class='title'>DQL condition :** ! 1+1
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-> 1
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</pre>
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The last example produces 1 because the
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expression evaluates the same way as
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(!1)+1.
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</li>
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<li>
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<a name="function_and"></a>
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<a class="indexterm" name="id2965271"></a>
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<a class="indexterm" name="id2965283"></a>
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AND
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Logical AND. Evaluates to 1 if all
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operands are non-zero and not NULL, to
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0 if one or more operands are
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0, otherwise NULL is
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returned.
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<b class='title'>DQL condition :** 1 AND 1
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-> 1
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<b class='title'>DQL condition :** 1 AND 0
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-> 0
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<b class='title'>DQL condition :** 1 AND NULL
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-> NULL
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<b class='title'>DQL condition :** 0 AND NULL
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-> 0
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<b class='title'>DQL condition :** NULL AND 0
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-> 0
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</pre>
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</li>
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<li>
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OR
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Logical OR. When both operands are
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non-NULL, the result is
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1 if any operand is non-zero, and
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0 otherwise. With a
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NULL operand, the result is
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1 if the other operand is non-zero, and
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NULL otherwise. If both operands are
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NULL, the result is
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NULL.
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<b class='title'>DQL condition :** 1 OR 1
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-> 1
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<b class='title'>DQL condition :** 1 OR 0
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-> 1
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<b class='title'>DQL condition :** 0 OR 0
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-> 0
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<b class='title'>DQL condition :** 0 OR NULL
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-> NULL
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<b class='title'>DQL condition :** 1 OR NULL
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-> 1
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</pre>
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</li>
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<li>
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<a name="function_xor"></a>
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<a class="indexterm" name="id2965520"></a>
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XOR
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Logical XOR. Returns NULL if either
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operand is NULL. For
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non-NULL operands, evaluates to
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1 if an odd number of operands is
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non-zero, otherwise 0 is returned.
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<b class='title'>DQL condition :** 1 XOR 1
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-> 0
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<b class='title'>DQL condition :** 1 XOR 0
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-> 1
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<b class='title'>DQL condition :** 1 XOR NULL
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-> NULL
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<b class='title'>DQL condition :** 1 XOR 1 XOR 1
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-> 1
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</pre>
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a XOR b is mathematically equal to
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(a AND (NOT b)) OR ((NOT a) and b).
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</li>
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