linux下c程序使用postgresql 8.4連接數據庫時編譯出現的問題。
1.
問題:In function `main':
`PGconn' undeclared (first use in this function)
`PGresult' undeclared (first use in this function)
`CONNECTION_BAD' undeclared (first use in this function)
`PGRES_COMMAND_OK' undeclared (first use in this function)
`PGRES_TUPLES_OK' undeclared (first use in this function)
出現此問題,為缺少#include <libpq-fe.h>
2.
問題:libpq-fe.h: No such file or directory
解決:系統未查找到libpq-fe.h,需要指定其目錄
方式1:gcc -c -I/usr/local/pgsql/include test.c
方式2:Makefile文件中,CPPFLAGS += -I/usr/local/pgsql/include
3.編譯.c至.o通過,但鏈接時出現如下問題
In function `main':
undefined reference to `PQsetdbLogin'
undefined reference to `PQstatus'
undefined reference to `PQerrorMessage'
解決:此為缺少鏈接所需的庫文件導致,需手動指定其目錄
undefined reference to `PQsetdbLogin'
undefined reference to `PQstatus'
undefined reference to `PQerrorMessage'
解決:此為缺少鏈接所需的庫文件導致,需手動指定其目錄
gcc -o test test1.o test2.o -L/usr/local/pgsql/lib -lpq
編譯成功。
參考:http://www.postgresql.org/docs/8.4/interactive/libpq-build.html
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