Combining Multiple SELECT and CREATE queries in MySQL - mysql

Question

In a PHP file I have multiple queries because I work with multiple tables, and with the data I get a and display such data. These queries could be merged into one? If anyone knows how I want to tell me what the code is like:
SELECT * FROM compras ;
SELECT * FROM clientes WHERE idcliente = '$row[idcliente]'
SELECT * FROM pedidos_ventas WHERE idcompra = '$row[idcompra]'
SELECT * FROM mercaderias WHERE idmerc = '$rowped[idmercaderia]' LIMIT 1
CREATE TABLE IF NOT EXISTS `clientes` (
`idcliente` INT(10) NOT NULL AUTO_INCREMENT,
`nombre` VARCHAR(50) NOT NULL,
`apellido` VARCHAR(50) NOT NULL,
`domicilio` VARCHAR(50) NOT NULL,
`telefono` VARCHAR(50) DEFAULT NULL,
`movil` VARCHAR(50) DEFAULT NULL,
`dni` VARCHAR(10) NOT NULL,
`familiar` VARCHAR(50) NOT NULL,
PRIMARY KEY (`idcliente`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1;
CREATE TABLE IF NOT EXISTS `compras` (
`idcompra` INT(7) NOT NULL AUTO_INCREMENT,
`idcliente` INT(7) NOT NULL,
`observacion` text NOT NULL,
`fecha_ingreso` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`idcompra`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `entregas_ventas` (
`identrega` INT(11) NOT NULL AUTO_INCREMENT,
`idcompra` INT(11) NOT NULL,
`entrega` DOUBLE(7,2) NOT NULL,
`fecha` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`identrega`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `mercaderias` (
`idmerc` INT(7) NOT NULL AUTO_INCREMENT,
`cantidad` INT(5) NOT NULL,
`codigo` VARCHAR(20) NOT NULL,
`producto` VARCHAR(100) NOT NULL,
`preciofinal` DOUBLE(7,2) NOT NULL,
PRIMARY KEY (`idmerc`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `pedidos_ventas` (
`idpedido` INT(7) NOT NULL AUTO_INCREMENT,
`idcompra` INT(7) NOT NULL,
`idmercaderia` INT(7) NOT NULL,
`kilo` DOUBLE(7,2) NOT NULL,
`precio` DOUBLE(7,2) NOT NULL,
PRIMARY KEY (`idpedido`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
select compras.idcompra, case when clientes.idcliente is null
then 'ninguno' else CONCAT(clientes.nombre, ',', clientes.apellido)
end as nombre, case when pedidos_ventas.idmercaderia = '-1' then 'Vianda saludable' when pedidos_ventas.idmercaderia = '-2' then 'Comida Sana' else mercaderias.producto end as mercaderia, pedidos_ventas.kilo, pedidos_ventas.precio from compras
left join clientes on (compras.idcliente=clientes.idcliente)
left join pedidos_ventas on (pedidos_ventas.idcompra=compras.idcompra)
left join mercaderias on (pedidos_ventas.idmercaderia=mercaderias.idmerc)
order by compras.idcompra asc
If now I would like to use the LIKE to see if it matches a value that I enter in an input $ _POST ['search'], either by customer name, vianda(lunch-box), food, or any merchandise ?? Try to do this and it does not work
SELECT compras.idcompra, CASE WHEN clientes.idcliente IS NULL
THEN 'ninguno' ELSE CONCAT(clientes.nombre, ',', clientes.apellido)
END AS nombre, CASE WHEN pedidos_ventas.idmercaderia = '-1' THEN 'Vianda saludable' WHEN pedidos_ventas.idmercaderia = '-2' THEN 'Comida Sana' ELSE mercaderias.producto END AS mercaderia, pedidos_ventas.kilo, pedidos_ventas.precio FROM compras
LEFT JOIN clientes ON (compras.idcliente=clientes.idcliente)
LEFT JOIN pedidos_ventas ON (pedidos_ventas.idcompra=compras.idcompra)
LEFT JOIN mercaderias ON (pedidos_ventas.idmercaderia=mercaderias.idmerc) WHERE mercaderias.producto LIKE '%comida%' OR..... LIKE clientes... or LIKE ..
ORDER BY compras.idcompra ASC

Answer 1

For a query with your current schema, try the following:
SELECT * FROM compras
INNER JOIN clientes ON (compras.idcliente = clientes.idcliente)
INNER JOIN pedidos_ventas ON (compras.id = pedidos_venta.id)
INNER JOIN mercaderias ON (pedidos_ventas.idmercaderia = mercaderias.idmerc)
WHERE clientes.idcliente = :clienteid
AND compras.idcompra = :compraid
AND mercaderias.idmerc = :mercaderiaid
IDEAL DATABASE DESIGN
Try adding foreign keys to your schema:
CREATE TABLE IF NOT EXISTS `cliente` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`nombre` VARCHAR(50) NOT NULL,
`apellido` VARCHAR(50) NOT NULL,
`domicilio` VARCHAR(50) NOT NULL,
`telefono` VARCHAR(50) DEFAULT NULL,
`movil` VARCHAR(50) DEFAULT NULL,
`dni` VARCHAR(10) NOT NULL,
`familiar` VARCHAR(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1;
CREATE TABLE IF NOT EXISTS `mercaderia` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`cantidad` INT(5) NOT NULL,
`codigo` VARCHAR(20) NOT NULL,
`producto` VARCHAR(100) NOT NULL,
`preciofinal` DOUBLE(7,2) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `compra` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`cliente_id` INT(10) NOT NULL,
`observacion` text NOT NULL,
`fecha_ingreso` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
CONSTRAINT `fk_compra_cliente`
FOREIGN KEY (`cliente_id`)
REFERENCES `cliente` (`id`)
ON DELETE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `entregas_venta` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`compra_id` INT(10) NOT NULL,
`entrega` DOUBLE(7,2) NOT NULL,
`fecha` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
CONSTRAINT `fk_entregas_venta_compra`
FOREIGN KEY (`compra_id`)
REFERENCES `compra` (`id`)
ON DELETE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `pedidos_venta` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`compra_id` INT(10) NOT NULL,
`mercaderia_id` INT(10) NOT NULL,
`kilo` DOUBLE(7,2) NOT NULL,
`precio` DOUBLE(7,2) NOT NULL,
PRIMARY KEY (`id`),
CONSTRAINT `fk_pedidos_venta_compra`
FOREIGN KEY (`compra_id`)
REFERENCES `compra` (`id`)
ON DELETE NO ACTION,
CONSTRAINT `fk_pedidos_venta_mercaderia`
FOREIGN KEY (`mercaderia_id`)
REFERENCES `mercaderia` (`id`)
ON DELETE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
And then use the query:
$stmt = $pdo->prepare(<<<SQL
SELECT * FROM compra
INNER JOIN cliente ON (compra.cliente_id = cliente.id)
INNER JOIN pedidos_venta ON (compra.id = pedidos_venta.id)
INNER JOIN mercaderia ON (pedidos_venta.mercaderia_id = mercaderia.id)
WHERE cliente.id = :clienteid
AND compra.id = :compraid
AND mercaderia.id = :mercaderiaid
SQL
);
$stmt->execute(':clienteid' => $clienteid, ':compraid' => $compraid, ':mercaderiaid' => $mercaderiaid);