logical and operator

基本解釋

Consider using parentheses to improve readability and avoid mistakes because of logical operator precedence.
考慮使用括號來改善可讀性和避免由于邏輯操作符的優(yōu)先級導致的錯誤。
A logical operator that consists of a logical AND followed by a logical NOT and returns a false value only if both operands are true.
由邏輯與和其后的邏輯非組成的邏輯運算符，如果兩個運算域都是真，則返回的值便為假。
It's best to read such execution plans from the left-lowest operator in the tree, since the logical flow in the plan is from bottom to top and left to right.
因為執(zhí)行計劃中的邏輯流是自下而上、從左到右，所以看此類執(zhí)行計劃時，最好是從樹中左下方的操作符開始。