▪ Overview of The SQL Query Language ▪ SQL Data Definition ▪ Basic Query Structure of SQL Queries ▪ Additional Basic Operations ▪ Set Operations ▪ Null Values ▪ Aggregate Functions ▪ Nested Subqueries ▪ Modification of the Database
01 孕产妇常见病原微生物 Maternal Common Pathogens 02 妊娠期常见感染性疾病 Common Infectious Diseases During Pregnancy 03 围产期抗菌药物的应用 Application of antibiotics in perinatal period 04 孕产妇抗菌药物的合理选择 Rational Choice of Antibiotic Drug in Maternal