DML触发器是SQL Server数据库中应用最广泛的触发器,在维护数据完整性、提高数据安全性、满足复杂的数据约束等方面具有重要作用。文中对DML触发器的应用进行详细研究。首先,介绍了DML触发器包含的AFTER和INSTEAD OF两种类型;其次,通过图形表示了AFTER触发器的触发顺序,并阐明了指定触发顺序需要注意的问题;然后,研究INSERT、DELETE、UPDATE三类触发器的工作原理;最后,给出了DML触发器的几个应用技巧。实际运用时要结合文中的研究内容进行详细设计,以便提高数据库系统的整体性能。

DML trigger is the trigger that most widely used in SQL Server database,and plays an important role in maintaining data integ-rity,improving data security,and meeting complex data constraints. Study the application of DML trigger in detail. First,introduce the two types of AFTER and INSTEAD OF that included in DML trigger;Second,show the trigger sequence of AFTER trigger through a graph-ical,and clarify the needing attention problems of specified trigger;Then research the working principle of the three class triggers of IN-SERT,DELETE and UPDATE;Finally,give several application skills of DML trigger. The practical application does the detail design should combine this contents in order to improve the overall performance of database system.

目的探讨腕管综合征合并神经根型颈椎病患者神经传导测定特点并进行临床分析,为治疗提供可靠的依据。方法选取该院2010年12月—2012年12月收治的腕管综合征合并神经根型颈椎病患者30例,并选择同期健康体检者30例作为对照研究。测定正中神经和尺神经的感觉传导末端潜伏期(DSL)、感觉神经动作电位(SNAP)、跨腕关节感觉传导速度(SCV)、运动传导末端潜伏期(DML)及复合肌肉动作电位(CMAP)。从感觉传导到运动传导逐一测量。正中神经压迫试验5min后再重复测量上述指标。结果观察组正中神经DSL较对照组显著延长,差异有统计学意义(P0.05);DML虽有延长,但与对照组相比,差异无统计学意义(P0.05)。而观察组尺神经和对照组正中神经及尺神经的各参数均无显著改变(P0.05)。观察组正中神经DSL和DML均明显延长,与对照组相比(P0.05),两组尺神经DSL和DML均无显著改变(P0.05)。结论腕管综合征合并神经根型颈椎病患者因正中神经的受压使腕管综合征患者正中神经的感觉传导末端潜伏时间明显延长,通过神经传导测定有助于对早期腕管综合征的诊断率。

Objective To analyze the nerve conduction characteristics of carpal tunnel syndrome patients with cervical spondylotic ra -diculopathy ,and to provide a better way to treat carpal tunnel syndrome .Methods Thirty patients of carpal tunnel syndrome with cer-vical spondylotic radiculopathy admitted to hospital from December 2011 to December 2012 were studied .And 30 healthy people were chosen as the control group .Distal sensory latency ( DSL) ,sensory nerve action potentials ( SNAP) ,cross-wrist sensory conduction ve-locity ( SCV) ,distal motor latency ( DML) and compound muscle action potential ( CMAP) of the median nerve and ulnar nerve were measured .We first tested sensory conduction ,and then measured motor conduction .These indicators were measured again 5 minutes af-ter median nerve compression test .Results Median nerve DSL of observation group was significantly longer than that of control group . The difference was statistically significant (P 0.05). Parameters of median nerve a

触发器技术是数据库设计与开发工作的重要内容,已广泛应用于数据库系统中。深入研究触发器技术,对于简化数据库操作、增强数据库安全性、提高开发效率等方面具有重要意义。文中在论述制定触发器计划的基础上,进行了四个方面的研究。研究DML和DDL两种触发器的分类并对二者进行比较;研究AFTER与INSTEAD OF触发器,包括二者的比较、触发时机和选择标准;研究触发器的嵌套和递归;研究DDL的数据库与服务器级触发器。

Trigger technology is an important content of the database design and development work,and it has been widely applied to the database system. Studying trigger technology deeply has a great significance to simplify database operations,enhance database security, improve development efficiency. In this paper,research four aspects based on discussing the trigger plan. Research the classification of DML and DDL triggers and compare the two;research AFTER and INSTEAD OF triggers,including a comparison of the two,trigger tim-ing and selection criteria;research the nest and recursive of trigger;research DDL database and server level trigger.

目的观察职业性慢性正己烷中毒患者神经肌电图(EMG)特征。方法选取职业性慢性正己烷中毒患者30例,分为轻、中、重度中毒3组,均在患者发病6个月时进行神经传导功能和肌电图检查并分析各指标的变化。结果 30例患者中,有7例患者腓总神经运动传导未引出动作电位,有2例患者腓肠神经未引出动作电位,其余患者所检神经均可引出。运动神经传导功能检查表现为运动神经传导速度(MCV)减慢、远端运动潜伏期(DML)延长和波幅降低,感觉神经传导功能检查表现为感觉神经传导速度(SCV)减慢和感觉神经动作电位波幅(SNAPA)降低。30例患者同一条神经左右侧上述各指标比较,差异均无统计学意义(P0.05)。3组患者左侧尺神经以及左、右侧腓总神经MCV分别比较,右侧尺神经DML比较,左、右侧的正中神经、尺神经和腓总神经波幅分别比较,左侧正中神经以及左、右侧尺神经SCV分别比较,左侧正中神经SNAPA比较,差异均有统计学意义(P0.05)。肌电图检查示,在安静状态下有67.7%出现自发电位,其中37.3%以复合重复放电为主,而纤颤电位和正锐波较少;肌肉小力收缩时有29.9%出现运动单位动作电位(MUAP)平均时限延长,14.9%未引出MUAP;肌肉大力收缩时募集电位多呈单纯相。结论职业性慢性正己烷中毒患者的EMG表现为感觉、运动混合型损害,神经轴索损害与脱髓鞘共存,左右对称发病,且有下肢神经运动传导受累程度较上肢严重等特点。

Objective To observe electromyography ( EMG) features in patients with occupational chronic n-hexane poi-soning.Methods According to the diagnostic conclusion , 30 patients with occupational chronic n-hexane poisoning were divided into mild, moderate and severe poisoning group .Nerve conduction test and EMG examination were conducted 6 months after the onset of the poisoning and the changes of each index were analyzed .Results Among 30 patients, peroneal nerve motor conductional action potentials were not elicited in 7 patients, sural nerve action potentials were not elicited in 2 cases, while others could be elicited in the rest of the patients .Motor nerve conduction function examination showed motor nerve conduction velocity (MCV) was slowed, distal motor latency (DML) was prolonged and the amplitude was decreased.Sensory conduction showed sensory nerve conduction velocity (SCV) was slowed and sensory nerve action po-tential amplitude ( SNAPA) was decreased .Analysis on parameters o

目的：探讨电生理参数异常分布用于诊断格林巴利综合征的价值。方法选取40例格林巴利综合征患者作为研究对象，进行电生理检查。记录肢体两侧、上下肢及远近端运动神经末端潜伏期（DML）、运动传导速度（MCV）、肌肉复合动作电位（CMAP）和感觉传导速度（SCV）。结果 F波潜伏期轻度异常、中度异常及重度异常分别为18．3％、6．2％和5．3％，合计29．8％；F波出现率轻度异常、中度异常及重度异常分别为9．3％、9．8％和15．6％，合计66．9％。感觉传导速度异常率为57．5％，运动传导速度异常率为75．7％，两组差异具有统计学意义（χ2＝5．34，P＜0．05）。双侧胫神经检测显示轻、中、重型患者H-反射异常率分别为78．0％、80．9％和100．0％，三者间差异无统计学意义（Uc＝1．47，P＞0．05）。近端和远端运动神经重度受损率分别为48．3％和74．5％，两者差异具有统计学意义（χ2＝9．86，P＜0．05）。上肢近端神经重度受损率为51．4％，显著低于上肢远端的71．6％，下肢近端神经重度受损率为44．2％，显著低于下肢远端的81.6％，差异均有统计学意义（χ2＝8．86、12．43，均P＜0．05）。结论电生理参数检测对格林巴利综合征的诊断具有较高价值，可以准确反应患者神经功

Objective To investigate diagnosis value of abnormal distribution of electrophysiological parame -ters in Guillain-Barre syndrome .Methods 40 cases of Guillain-Barre syndrome were chosen as an object of study ,all patients electrophysiological examination .Record limbs on both sides ,upper and lower extremities and proximal and distal motor nerve distal latency ( DML ) , motor conduction velocity ( MCV ) , compound muscle action potential (CMAP)and sensory conduction velocity (SCV) were recorded.Results F wave latency mildly abnormal ,moderately abnormal and severe abnormalities were 18.3 %,6.2 %and 5.3%,totaling 29.8%,F-wave occurrence rate mildly abnormal,moderately abnormal and severe abnormalities were 9.3 %9.8%and 15.6%,totaling 66.9%.Abnormal sensory conduction velocity was 57.5%,motor conduction velocity anomaly was 75.7%, there was a statistically sig-nificant difference between the two groups (χ2 =5.34,P 0.05).3 proximal and distal motor nerve severe damage rates we