From 3c85ec0c7c6d2f78f928495c0907edb57efb1389 Mon Sep 17 00:00:00 2001 From: notstingy <2095966259@qq.com> Date: Fri, 19 Jun 2026 23:20:23 +0800 Subject: [PATCH] multivalued dependency --- docs/sys/db/7.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/docs/sys/db/7.md b/docs/sys/db/7.md index 45232a90d..1a1c3d74e 100755 --- a/docs/sys/db/7.md +++ b/docs/sys/db/7.md @@ -581,9 +581,9 @@ FROM ( $$ t_1[\alpha] = t_2[\alpha] = t_3[\alpha] = t_4[\alpha] \\ t_3[\beta] = t_1[\beta] \\ -t_3[R - \beta] = t_2[R - \beta] \\ +t_3[R - \alpha - \beta] = t_2[R - \alpha - \beta] \\ t_4[\beta] = t_2[\beta] \\ -t_4[R - \beta] = t_1[R - \beta] +t_4[R - \alpha - \beta] = t_1[R - \alpha - \beta] $$ 那么在 $R$ 上的多值依赖 $\alpha \twoheadrightarrow \beta$ 有效。下面用表格来表示上述五个等式： @@ -698,4 +698,4 @@ $$ \ No newline at end of file +