任何人都可以告诉我MySql Select字段数的限制，我的意思是我们可以在Mysql Select查询中使用多少个字段？
例如：SELECT field1，field2，field3，... field-N FROM 表1
N的最大值是什么？
答案 0 :(得分：2)
我没有在MySQL参考中的 public Bitmap mergeBitmap(Bitmap backBitmap, Bitmap frontBitmap)
{
Bitmap bitmap = backBitmap.Copy(Bitmap.Config.Argb8888, true);
Canvas canvas = new Canvas(bitmap);
//this Rect will decide which part of your frontBitmap will be drawn,
//(0,0,frontBitmap.Width, frontBitmap.Height) means that the whole of frontBitmap will be drawn,
//(0,0,frontBitmap.Width/2, frontBitmap.Height/2) means that the half of frontBitmap will be drawn.
Rect frontRect = new Rect(0, 0, frontBitmap.Width, frontBitmap.Height);
//this Rect will decide where the frontBitmap will be drawn on the backBitmap,
//(200, 200, 200+ frontBitmap.Width, 200+frontBitmap.Height) means that
//the fontBitmap will drawn into the Rect which left is 200, top is 200, and its width and
//height are your frontBitmap's width and height.
//I suggest the baseRect's width and height should be your fontBitmap's width and height,
//or, your fontBitmap will be stretched or shrunk.
Rect baseRect = new Rect(200, 200, 200+ frontBitmap.Width, 200+frontBitmap.Height);
canvas.DrawBitmap(frontBitmap, frontRect, baseRect, null);
return bitmap;
}
子句中找到最大列数，但我确实找到了maximum number of columns in a table, which is 4096（或者远远少于InnoDb等的ymmv）。
我很抱歉我无法给出明确答案，但我确实想到了三个可能的答案：
SELECT中的最大列数正是4096 ，因为SELECT有效地创建了一个表格。SELECT中的最大列数为 4096 的倍数，因此您可以选择并加入多个表格。无论哪种方式，我都会说答案足够：我无法想象你需要选择超过4096列的情况，如果你这样做，你可能会遇到其他问题（超时）首先。