Syscat.tabconst Contains a row for each unique (u), primary key (p), foreign key (f), or table check (k) constraint db2 select constname, tabname, type from syscat.tabconst.
tabconst为每个唯一性(U)、主键(p)、外键(f)或者表检查(K)约束保持一个行db2 select constname, tabname, type from syscat . tabconst。