Objective-C sqlite 在 LIKE 子句中添加查询参数 [英] Objective-C sqlite adding query parameter inside of LIKE clause

问题描述

我通过 C API 在 Objective-C 中使用 sqlite.我的应用程序的预期功能之一是，用户可以搜索人名，并且对于他们输入的每个新字符，都会执行使用 LIKE 的 SQL 查询以查找所有姓名符合匹配条件的人.我遇到的问题是在 LIKE 中参数化匹配，而没有按字面解释问号.也就是说，我相信该应用目前正在寻找其中包含 ? 的人名(即没有人).

I am using sqlite in Objective-C via the C API. One of the intended features of my app is that the user can search for a person name and with each new character they enter, an SQL query using LIKE is executed to find all people whose names qualify as a match. The issue I am running into is parameterizing the match inside the LIKE, without the question mark being interpreted literally. That is, I believe the app at present is looking for people's names that include ? in them (which is nobody).

我的代码如下所示:

const char *sql = "SELECT rowid, name, email FROM person WHERE name LIKE '%?%'";
sqlite3_stmt *sqlStatement;
if(sqlite3_prepare_v2(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK) {
    NSLog(@"Problem preparing getFilteredPeopleStubs statement.");
}
if(sqlite3_bind_text(sqlStatement, 1, [searchText UTF8String], -1, SQLITE_TRANSIENT) != SQLITE_OK){
    NSLog(@"Problem binding search text param.");
}

基本上，searchText 是我想要名字的来源，但目前我相信它只是在搜索名字包含的人?，因为 '%?%' 中的单引号.是否有解决此问题的方法仍然可以让我使用参数化查询(防止 SQL 注入)并实现我所追求的目标?

Basically, searchText is where I want the name to be coming from, but at the moment I believe it is just searching for people whose name contains ?, because of the single quotations in '%?%'. Is there a solution to this problem that still lets me use a parameterized query (protection against SQL injection) and achieves what I am after?

推荐答案

将 % 字符放入 searchText 中，就像(原谅双关语)这样:

Put the % characters into searchText, like (excuse the pun) this:

const char *sql = "SELECT rowid, name, email FROM person WHERE name LIKE ?";
sqlite3_stmt *sqlStatement;
if(sqlite3_prepare_v2(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK) {
    NSLog(@"Problem preparing getFilteredPeopleStubs statement.");
}
NSString *bindParam = [NSString stringWithFormat:@"%%%@%%", searchText];
if(sqlite3_bind_text(sqlStatement, 1, [bindParam UTF8String], -1, SQLITE_TRANSIENT) != SQLITE_OK){
    NSLog(@"Problem binding search text param.");
}

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