outs.dat

c语言小程序100个

n any field.  Yu can create an index 
rd.   yu have the crrect rec
 be used    Yu can create an index n any field, n several fields t
 use as a key. The      tgether, r n parts theref, that yu want t
rds and define    keys in indexes allw yu quick access t specific rec
nger       rders fr sequential prcessing f a ISAM file. After yu n l
 effect   need an index, yu can delete it. Additin and indexes have n
ther indexes.     n the data recrds r n 
 uniquely identify that   Yu may want a field in field in each recrd t
yee      recrd frm all ther recrds in the file. Fr example, the Empl
     Number field is unique if yu d nt assign the same number t tw
ther    different emplyees, and yu never reassign these numbers t 
 a        emplyees. If yu wish t find r mdify the recrd belnging t
f determining   specific emplyee, this unique field saves the thuble 
rd.   whether yu have the crrect rec
rd     If yu d nt have a unique field, yu must find the first rec
u    the matches yur key and determine whether the recrd is the ne y
thers.      want. If it is nt the crrect ne, yu must search again t find 
u      If yu knw that yu have a unique field within yur recrds, y
nly   can include this fact in the key descriptin, and ISAM will allw 
yee numbers are   unique keys. Fr example, if yu specify that the empl
r change      unique, ISAM nly lets yu add recrds t the file fr, 
t alreadly exist int file.     numbers t, emplyee numbers that d n