feat: add create_table

create_table/main.c

@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <libpq-fe.h>
+
+void do_exit(PGconn *conn, PGresult *res) {
+  fprintf(stderr, "%s\n", PQerrorMessage(conn));
+  /*every statement result should be freed*/
+  PQclear(res);
+  /*close connection and free memory*/
+  PQfinish(conn);
+  exit(EXIT_FAILURE);
+}
+
+int main(int argc, char **argv) {
+  /*declaration*/
+  const char *conninfo;
+  
+  printf("main() Started...\n");
+
+  /*read command line*/
+  if (argc > 1){
+    printf("main() argv[1]: %s\n", argv[1]);
+    conninfo = argv[1];
+  }else{
+    printf("call ./main <connection info>\n");
+    return 1;
+  }
+
+  /*connect to database*/
+  PGconn *conn = PQconnectdb(conninfo);
+  if (PQstatus(conn) == CONNECTION_BAD) {
+    fprintf(stderr, "Connection to database failed: %s\n",
+            PQerrorMessage(conn));
+    PQfinish(conn);
+    exit(1);
+  }else if(PQstatus(conn)==CONNECTION_OK){
+    printf("main() connected to database\n");
+  }else{
+    printf("main() connection status NOT known\n");
+  }
+
+  char *user = PQuser(conn);
+  char *db_name = PQdb(conn);
+  char *pswd = PQpass(conn);
+  printf("User: %s\n", user);
+  printf("Database name: %s\n", db_name);
+  printf("Password: %s\n", pswd);
+
+  /*submit SQL statement to the server and wait for the result*/
+  PGresult *res = PQexec(conn, "DROP TABLE IF EXISTS cars_cleanup");
+
+  if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+    do_exit(conn, res);
+  }else{
+    printf("main() database table cleaned\n");
+  }
+  /*every statement result should be freed*/
+  PQclear(res);
+
+  res = PQexec(conn, "CREATE TABLE cars_cleanup(Id INTEGER PRIMARY KEY, Name VARCHAR(20), Price INT)");
+  if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+    do_exit(conn, res);
+  }else{
+    printf("main() database table created\n");
+  }
+  /*every statement result should be freed*/
+  PQclear(res);
+
+  res = PQexec(conn, "INSERT INTO cars_cleanup VALUES(1,'Audi',52642)");
+  if (PQresultStatus(res) != PGRES_COMMAND_OK){
+    do_exit(conn, res);
+  }else{
+    printf("main() record inserted into database table\n");
+  }
+  /*every statement result should be freed*/
+  PQclear(res);
+
+  res = PQexec(conn, "INSERT INTO cars_cleanup VALUES(2,'Mercedes',57127)");
+  if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+    do_exit(conn, res);
+  }else{
+    printf("main() record inserted into database table\n");
+  }
+  /*every statement result should be freed*/
+  PQclear(res);
+
+  PQfinish(conn);
+  return 0;
+}
+

create_table/makefile

@@ -0,0 +1,24 @@
+# Docu
+#
+#$@ is the name of the file to be made
+#$? is the names of the changed dependents
+#$< the name of the related file that caused the action
+#$* the prefix shared by target and dependent files
+#
+# Others
+RM      = /bin/rm -f
+#
+# Source, Executable, Includes, Library Defines
+EXE    = main
+#
+# Compiler, Linker Defines
+CC      = /usr/bin/gcc
+#
+all: main.o
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+#
+main.o:
+	$(CC) -c main.c -I/usr/include/postgresql
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

create_table/makefile-fine

@@ -0,0 +1,21 @@
+# Docu
+#
+#$@ is the name of the file to be made
+#$? is the names of the changed dependents
+#$< the name of the related file that caused the action
+#$* the prefix shared by target and dependent files
+#
+# Others
+RM      = /bin/rm -f
+#
+# Source, Executable, Includes, Library Defines
+EXE    = main
+#
+# Compiler, Linker Defines
+CC      = /usr/bin/gcc
+#
+all:
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

create_table/makefile-fine2

@@ -0,0 +1,24 @@
+# Docu
+#
+#$@ is the name of the file to be made
+#$? is the names of the changed dependents
+#$< the name of the related file that caused the action
+#$* the prefix shared by target and dependent files
+#
+# Others
+RM      = /bin/rm -f
+#
+# Source, Executable, Includes, Library Defines
+EXE    = main
+#
+# Compiler, Linker Defines
+CC      = /usr/bin/gcc
+#
+all: main.o
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+#
+main.o:
+	$(CC) -c main.c -I/usr/include/postgresql
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

create_table/readme.md

@@ -0,0 +1,23 @@
+* build
+
+```
+make
+```
+
+* run
+
+```
+./main 'postgresql://begerad:secret@localhost:5432/sib00_vbn_gtfs'
+```
+
+* or run
+
+```
+./main 'postgresql://begerad:secret@localhost:5432/vbn_data'
+```
+
+* or run
+
+```
+./main "host=localhost port=5432 user=begerad password=<secret> dbname=vbn_data"
+```

server-version/main.c

@@ -3,9 +3,10 @@
 #include <libpq-fe.h>
 
 void do_exit(PGconn *conn) {
+  fprintf(stderr, "%s\n", PQerrorMessage(conn));
   /*close connection and free memory*/
   PQfinish(conn);
-  exit(EXIT_SUCCESS);
+  exit(EXIT_FAILURE);
 }
 
 int main(int argc, char **argv) {
@@ -19,7 +20,8 @@ int main(int argc, char **argv) {
     printf("main() argv[1]: %s\n", argv[1]);
     conninfo = argv[1];
   }else{
-    conninfo = "dbname=postgres";
+    printf("call ./main <connection info>\n");
+    return 1;
   }
 
   /*connect to database*/
@@ -46,5 +48,6 @@ int main(int argc, char **argv) {
   int ver = PQserverVersion(conn);
   printf("Server version: %d\n", ver);
 
-  do_exit(conn);
+  PQfinish(conn);
+  return 0;
 }