MySQL 9.0.0
Source Code Documentation
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This is used for segregating rows in groups (e.g. More...
#include <item.h>
Public Member Functions | |
virtual | ~Cached_item ()=default |
virtual bool | cmp ()=0 |
Compare the value associated with the item with the stored value. More... | |
Item * | get_item () const |
Item ** | get_item_ptr () |
Public Attributes | |
bool | null_value {true} |
Protected Member Functions | |
Cached_item (Item *i) | |
Protected Attributes | |
Item * | item |
The item whose value to cache. More... | |
This is used for segregating rows in groups (e.g.
GROUP BY, windows), to detect boundaries of groups. It caches a value, which is representative of the group, and can compare it to another row, and update its value when entering a new group.
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inlineexplicitprotected |
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virtualdefault |
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pure virtual |
Compare the value associated with the item with the stored value.
If they are different, update the stored value with item's value and return true.
Implemented in Cached_item_str, Cached_item_json, Cached_item_real, Cached_item_int, Cached_item_temporal, and Cached_item_decimal.
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inline |
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inline |
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protected |
The item whose value to cache.
bool Cached_item::null_value {true} |