Table Join

Algebric functions like Sum,Min,Max etc are implemented here.
This page uses the following methods:

• await presql.join(<filter>)
• await presql.hasOne('').{function} -Comming Soon

Note that

id is the default foreign key then do not use joinOn field, it will done automatically.
If you have custom foreign key enable by you or you want to use own foreign key only then use joinOn and define columns name

Incorrect Use if id is the foreign key

 relation: {
      joinType: "inner", // inner,left,right,self,full
      joinOn: {
        fromColumn: "id",
        joinColumn: "id",
      },
      where: { email: "[email protected]" },
      sortBy: {
        id: true,  
        asc: true,
      },
      }

Correct Use if id is the foreign key

relation: {
      joinType: "inner", // inner,left,right,self,full   
      where: { email: "[email protected]" },
      sortBy: {
        id: true,  
        asc: true,
      },
    },

Correct Use if custom/user foreign key

relation: {
      joinType: "inner",    
      where: { email: "[email protected]" },
        joinOn: {
        fromColumn: "from_table_foreign_key_column",
        joinColumn: "join_with_table_foreign_key_column",
      },
      sortBy: {
        id: true, 
        asc: true,
      },
    },

index.js

import presql from "./connection";

async function hasOne() {
  const data = await presql.join({
    table: "cart",
    from: "products", // larger table
    joinWith: "cart", // smalller table
    relation: {
      joinType: "inner", // inner,left,right,self,full
      joinOn: {
        fromColumn: "product_id",
        joinColumn: "product_id",
      }, //optional field if id is the foreign key, if not then specify columns here

      where: { email: "[email protected]" },
      sortBy: {
        id: true, // use this syntax
        asc: true,
      },
    },
  });
  console.log(data); // if showResults is true, it will print results
}

Query Preparing Before Join:

SELECT * FROM "from" joinType JOIN joinWith ON joinOn.fromColumn = joinOn.joinColumn WHERE `email` ='[email protected]' ;

Query Preparing After :

SELECT * FROM `products` INNER JOIN `cart` ON  products.product_id = cart.product_id WHERE `email` ='[email protected]'  ORDER BY id ASC;

Remember

table ,from,joinWith,relation, is required parameter ,select,where,sortBy are optional, use them to filter the data as per your own use

Write coloumn name: if table column join by some special characters please use cammelCase instead writing same as it is name Original Table Name : product_info

Correct Syntax : productInfo InCorrect Syntax : product_info. Define type property to use Math Functions.

relation: {
      joinType: "", // inner,left,right,self,full
      joinOn: {
        fromColumn: "product_id",
        joinColumn: "product_id",
      },
  }