Updates

Author: melchisedech333

2 - create table.c

@@ -22,11 +22,9 @@ int main (int argc, char *argv[])
 
     if (PQresultStatus(res) != PGRES_COMMAND_OK) {
         fprintf(stderr, "Drop error, %s\n", PQerrorMessage(conn));    
-
         PQclear(res);
-        PQfinish(conn);    
-
-        exit(1);
+        PQfinish(conn);
+        exit(0);
     }
 
     PQclear(res);
@@ -41,11 +39,9 @@ int main (int argc, char *argv[])
 
     if (PQresultStatus(res) != PGRES_COMMAND_OK) {
         fprintf(stderr, "Create error, %s\n", PQerrorMessage(conn));    
-
         PQclear(res);
-        PQfinish(conn);    
-
-        exit(1);
+        PQfinish(conn);
+        exit(0);
     }
 
     PQclear(res);

3 - insert item.c

@@ -37,13 +37,12 @@ int main (int argc, char *argv[])
 
     if (PQresultStatus(res) != PGRES_COMMAND_OK) {
         fprintf(stderr, "Insert error, %s\n", PQerrorMessage(conn));    
-
         PQclear(res);
-        PQfinish(conn);    
-
-        exit(1);
+        PQfinish(conn);
+        exit(0);
     }
 
+    PQclear(res);
     printf("Item successfully inserted into the database.\n");
 
     // Close connection.

4 - select all.c

@@ -16,7 +16,8 @@ int main (int argc, char *argv[])
     }
 
     printf("Connected!\n");
-
+    
+    // Run SQL command.
     PGresult *res = PQexec(conn, "SELECT * FROM example");    
 
     if (PQresultStatus(res) != PGRES_TUPLES_OK) {

5 - delete.c

@@ -17,6 +17,7 @@ int main (int argc, char *argv[])
 
     printf("Connected!\n");
 
+    // Delete data.
     PGresult *res = PQexec(conn, "DELETE FROM example");    
 
     if (PQresultStatus(res) != PGRES_COMMAND_OK) {

6 - update.c

@@ -0,0 +1,41 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libpq-fe.h>
+#include "settings.h"
+
+int main (int argc, char *argv[])
+{
+    // Connect to the database.
+    PGconn *conn = PQconnectdb("host=" HOSTNAME " dbname=" DATABASE " user=" USERNAME " password=" PASSWORD);
+
+    if (PQstatus(conn) == CONNECTION_BAD) {
+        fprintf(stderr, "Connection to database failed: %s\n", PQerrorMessage(conn));
+        PQfinish(conn);
+        exit(0);
+    }
+
+    printf("Connected!\n");
+
+    // Update data.
+    PGresult *res = PQexec(conn, "UPDATE example SET name = 'New name' WHERE id = 1");    
+
+    if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+        fprintf(stderr, "Update error, %s\n", PQerrorMessage(conn));    
+        PQclear(res);
+        PQfinish(conn);
+        exit(0);
+    }
+
+    printf("Items successfully updated.\n");
+    printf("Total: %d\n", atoi(PQcmdTuples(res)));
+    PQclear(res);
+
+    // Close connection.
+    PQfinish(conn);
+    printf("Disconnected!\n");
+
+    return 0;
+}
+
+

readme-pt.md

@@ -92,6 +92,7 @@ Códigos:
 - <b>3 - insert item.c</b>: Insere registros em uma tabela.
 - <b>4 - select all.c</b>: Seleciona os registros de uma tabela.
 - <b>5 - delete.c</b>: Exclui registros.
+- <b>6 - update.c</b>: Atualiza registros.
 
 <br>