Question

我是IOS和Sqlite3 DB的新手。

我想在sqlite3 DB和swift4中实现什么来获取表的总数。

我做了以下步骤。

func getTotalCount()->Int32{
    let queryStatementString = "SELECT COUNT(*) FROM Attendance"
    var stmt: OpaquePointer?

    print("select valid count \(queryStatementString) ")

    var totalCount: Int32 = 0
    var id: Int = 0

    if sqlite3_prepare_v2(db, queryStatementString, -1, &stmt, nil) == SQLITE_OK{
        if sqlite3_step(stmt) == SQLITE_ROW {
            id = Int(sqlite3_column_int(stmt, 0))
            print("id \(id)")
            totalCount = sqlite3_column_count(stmt!)
            print("db: validCount Result:")
            print("validCount \(totalCount)")

        }
    }

    if sqlite3_step(stmt) != SQLITE_DONE {
        let errmsg = String(cString: sqlite3_errmsg(stmt)!)
        print("db: failure getting punchTime: \(errmsg)")

    }

    return totalCount
}

但总是把我作为一个计数。我没有得到我失踪的地方。

Answer 1

我得到了答案。

我正在检索错误的索引值。

参考下面的代码。

func getTotalCount()->Int32{
    let queryStatementString = "SELECT COUNT(*) FROM Attendance"
    var stmt: OpaquePointer?
    var totalCount: Int32 = 0

    if sqlite3_prepare_v2(db, queryStatementString, -1, &stmt, nil) == SQLITE_OK{
        while sqlite3_step(stmt) == SQLITE_ROW {
            totalCount = sqlite3_column_int(stmt, 0)
            print("totalCount \(totalCount)")
        }
    }

    if sqlite3_step(stmt) != SQLITE_DONE {
        let errmsg = String(cString: sqlite3_errmsg(stmt)!)
        print("db: failure getting punchTime: \(errmsg)")
    }
    return totalCount
}

如何在swift4中获取Sqlite3中的表总数？

1 个答案: