ESP module connect and worked in PostgreSQL in Heroku - heroku

Question

I want to put a record in the PostgreSQL database of my application, which I deploy through the Heroku website(RoR).
I need to do this with ESP-01/12 module.
I can not find any complete example of connecting and executing the sql statement on the pg database in C.
My code:
#include <ESP8266WiFi.h>
/* Wi fi */
const char* ssid = "ssid";
const char* password = "password";
/* database */
const char* host = "***.compute-1.amazonaws.com";
const char* database = "database";
const char* user = "user";
const char* streamId = "???";
const char* privateKey = "password?";
void setup() {
delay(1000);
Serial.begin(115200); delay(10); Serial.println('\n');
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password); Serial.print("Connecting to "); Serial.print(ssid); Serial.println(" ...");
int i = 0;
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print(++i); Serial.print(' ');
}
Serial.println("Connection established!");
Serial.print("IP address:\t");
Serial.println(WiFi.localIP());
WiFi.printDiag(Serial);
}
void loop() {
delay(5000);
Serial.print("connecting to ");
Serial.println(host);
// Use WiFiClient class to create TCP connections
WiFiClient client;
const int httpPort = 5432;
if (client.connect(host, httpPort)) {
Serial.println("OK!");
}
client.print("psql -U user --password password? -p 5432 -h host -d database \r\n");
delay(10);
// Read all the lines of the reply from server and print them to Serial
while (client.available()) {
String line = client.readStringUntil('\r');
Serial.print(line);
}
Serial.println();
Serial.println("closing connection");
}
It seems to me that I connected to port 5432, but I do not know what to do next with the line below, to get some answer:
client.print()
I assume that after connecting to port 5432, I can send text that appears on the other side as on the command line and the psql program is available there. I made such a connection from the computer, the same line as in the code and I got access.
Help me, please get to my database from the ESP module in C. I noticed that despite entering the password after the psql command I have to give it again, but I can not register the answer of the command line coming from the other side, for example "please enter password".
Yes, I helped myself with a translator, I speak Polish.

Answer 1

client.print() is to write some data to the WifiClient. I think is some command on the Database. If you need to add data to the PostgreSQL Database you can create some API endpoint with the SQL queries. It will be solve your problem.
Refer this Repo
This will explains how to create a NodeJS API to capture the Data sent from ESP8266 and Write them into Firebase Database. You can clone it and change the Database part. Arduino part is same and You need to install the ArduinoJSON Library. Hope you understand.