blocks|key|281472|text|在MySQL中，like操作符是否区分大小写取决于列的类型和它们的排序规则(请参见http://dev.mysql.com/doc/refman/5.5/en/case-sensitivity.html)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|281473|Hibernate“仅仅”是SQL之上的一层。like操作符的约定是发布SQL+like操作符。如果希望MySQL和PostgreSQL的类型和排序规则相同，请在数据库模式中选择正确的类型和排序规则。但是Hibernate不能神奇地让所有的数据库使用相同的规则。|281474|设计你的应用程序，选择和设计你的数据库，这样你观察到的行为就是你期望的行为。|281475|PS+:但是我同意Hibernate的javadoc是...完美无瑕。|281476|entityMap|0|LINK|mutability|MUTABLE|url|http://dev.mysql.com/doc/refman/5.5/en/case-sensitivity.html^0|15|1O|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@$A|S|B|T|1|U]]|C|$]]|$1|D|3|E|5|6|7|V|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|W|8|@]|9|@]|C|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|C|$]]|$1|J|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|K|$L|$5|M|N|O|C|$P|Q]]]]

The case-sensitivity of the like operator, in MySQL, depends on the type of the columns and on their collation (see <a href="http://dev.mysql.com/doc/refman/5.5/en/case-sensitivity.html" rel="noreferrer">http://dev.mysql.com/doc/refman/5.5/en/case-sensitivity.html</a>). 

Hibernate is "just" a layer on top of SQL. The contract of the like operator is to issue a SQL like operator. If you want it to be the same for MySQL and PostgreSQL, then choose the right types and collations in the database schemas. But Hibernate can't magically make all the databases use the same rules.

Design your application, choose and design your database so that the behavior you observe is the behavior you expect. 

PS : but I agree that the javadoc of Hibernate is... perfectible.

blocks|key|279597|text|在PostgreSQL中有'ILIKE‘和'LIKE’不同的运算符，所以区分大小写独立于列属性，这就是发生这种情况的原因|type|unstyled|depth|inlineStyleRanges|entityRanges|data|279598|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In PostgreSQL there is 'ILIKE' and 'LIKE' different operators,
So case sensitivity in independent of column properties that's the reason this thing happens

blocks|key|279602|text|Hibernate的Criteria+API有Restrictions.ilike函数，该函数有如下契约：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|279603|A+case-insensitive+"like",+similar+to+Postgres+ilike+operator|code-block|syntax|javascript|279604|这很酷。但同样的类也有类似的功能，有更模糊的契约：|279605|Apply+a+"like"+constraint+to+the+named+property|279606|示例|279607|Criteria+cr+=+session.createCriteria(Employee.class);

//+To+get+records+having+fistName+starting+with+zara
cr.add(Restrictions.like("firstName",+"zara%25"));

//+Case+sensitive+form+of+the+above+restriction.
cr.add(Restrictions.ilike("firstName",+"zara%25"));|279608|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Hibernate's Criteria API has Restrictions.ilike function which has the following contract:

<pre><code>A case-insensitive "like", similar to Postgres ilike operator
</code></pre>

That's cool. But the same class also has like function, having much more vague contract:

<pre><code>Apply a "like" constraint to the named property
</code></pre>

example

<pre><code>Criteria cr = session.createCriteria(Employee.class);

// To get records having fistName starting with zara
cr.add(Restrictions.like("firstName", "zara%"));

// Case sensitive form of the above restriction.
cr.add(Restrictions.ilike("firstName", "zara%"));
</code></pre>

blocks|key|275945|text|ilike将使用较低的输入值，并使用较低的列值，例如|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|275946|select+*+from+table+where+lower(column)+like+lower(?)|275947|entityMap^0|0|5|0|0|1H|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

<code>ilike</code> will be doing a lower of your input value, and a lower of the column value e.g.

<code>select * from table where lower(column) like lower(?)</code>

Hibernate's <code>Criteria</code> API has <code>Restrictions.ilike</code> function which has the following contract:

<blockquote>
 A case-insensitive "like", similar to Postgres ilike operator
</blockquote>

That's cool. But the same class also has <code>like</code> function, having much more vague contract:

<blockquote>
 Apply a "like" constraint to the named property
</blockquote>

example

<pre><code>Criteria cr = session.createCriteria(Employee.class);

// To get records having fistName starting with zara
cr.add(Restrictions.like("firstName", "zara%"));

// Case sensitive form of the above restriction.
cr.add(Restrictions.ilike("firstName", "zara%"));
</code></pre>

Difference between Restrictions.like and .ilike in Hibernate Criteria API

PostgreSQL

数据库

MySQL

Hibernate的Criteria接口有Restrictions.ilike函数，该函数有如下契约：一个不区分大小写的"like"，类似于Postgres ilike操作符这很酷。但同样的类也有like函数，有更模糊的约定：将"like“约束应用于命名属性示例Criteria cr = session.createC...

问Hibernate标准应用编程接口中Restrictions.like与.ilike的区别
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