Android 在 SQLite 查询中使用 LIMIT 语句
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2497677/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Using the LIMIT statement in a SQLite query
提问by Mike Cialowicz
I have a query that selects rows in a ListViewwithout having a limit. But now that I have implemented a SharedPreferencesthat the user can select how much rows will be displayed in the ListView, my SQLite query doesn't work. I'm passing the argument this way:
我有一个查询，可以在ListView没有限制的情况下选择行。但是现在我已经实现了SharedPreferences用户可以选择将在 中显示的行数ListView，我的 SQLite 查询不起作用。我以这种方式传递论点：
return wDb.query(TABELANOME, new String[] {IDTIT, TAREFATIT, SUMARIOTIT}, CONCLUIDOTIT + "=1", null, null, null, null, "LIMIT='" + limite + "'");
回答by Mike Cialowicz
The equals (=) operator is not used with the LIMITclause. Remove it.
等号 ( =) 运算符不与LIMIT子句一起使用。去掉它。
Here's an example LIMITquery:
这是一个示例LIMIT查询：
SELECT column FROM table ORDER BY somethingelse LIMIT 5, 10
Or:
或者：
SELECT column FROM table ORDER BY somethingelse LIMIT 10
In your case, the correct statement would be:
在你的情况下，正确的说法是：
return wDb.query(TABELANOME, new String[] {IDTIT, TAREFATIT, SUMARIOTIT}, CONCLUIDOTIT + "=1", null, null, null, null, String.valueOf(limite));
Take a look here at the SQLite select syntax: http://www.sqlite.org/syntaxdiagrams.html#select-stmt
在此处查看 SQLite 选择语法： http://www.sqlite.org/syntaxdiagrams.html#select-stmt
This image is rather useful: http://www.sqlite.org/images/syntax/select-stmt.gif
回答by Jon O
For anyone stumbling across this answer looking for a way to use a LIMITclause with an OFFSET, I found out from this bugthat Android uses the following regex to parse the limit clause of a query:
对于任何在这个答案中绊倒寻找一种使用带有 的LIMIT子句的方法的人OFFSET，我从这个错误中发现 Android 使用以下正则表达式来解析查询的限制子句：
From <framework/base/core/java/android/database/sqlite/SQLiteQueryBuilder.java>
从 <framework/base/core/java/android/database/sqlite/SQLiteQueryBuilder.java>
LIMIT clause is checked with following sLimitPattern.
使用以下 sLimitPattern 检查 LIMIT 子句。
private static final Pattern sLimitPattern = Pattern.compile("\s*\d+\s*(,\s*\d+\s*)?");
Note that the regex does accept the format offsetNumber,limitNumbereven though it doesn't accept the OFFSETstatement directly.
请注意，正则表达式确实接受格式，offsetNumber,limitNumber即使它不OFFSET直接接受语句。
回答by Pepijn
Due to this bug which also doesn't allow for negative limits
由于这个错误也不允许负限制
8,-1
8,-1
I had to use this workaround
我不得不使用这个解决方法
SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
builder.setTables(table);
String query = builder.buildQuery(projection, selection, null, null, null, sortOrder, null);
query+=" LIMIT 8,-1";
