Understanding date type implicit conversion
When does oracle implicitly converts date type? on what parameters does it depend?
I am running the following:
<span class="kwd" style="color: #00008b;">SELECT</span><span class="pln" style="color: black;"> SYSDATE </span><span class="pun" style="color: black;">-</span><span class="pln" style="color: black;"> </span><span class="str" style="color: maroon;">'01-01-01'</span><span class="pln" style="color: black;"> </span><span class="kwd" style="color: #00008b;">FROM</span><span class="pln" style="color: black;"> DUAL</span>
and got :
<span class="kwd" style="color: #00008b;">SELECT</span><span class="pln" style="color: black;"> SYSDATE </span><span class="pun" style="color: black;">-</span><span class="pln" style="color: black;"> </span><span class="str" style="color: maroon;">'01-01-01'</span><span class="pln" style="color: black;"> </span><span class="kwd" style="color: #00008b;">FROM</span><span class="pln" style="color: black;"> DUAL </span><span class="pun" style="color: black;">*</span><span class="pln" style="color: black;"> ERROR at line </span><span class="lit" style="color: maroon;">1</span><span class="pun" style="color: black;">:</span><span class="pln" style="color: black;"> ORA-01722</span><span class="pun" style="color: black;">:</span><span class="pln" style="color: black;"> invalid number</span>
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