io.vertx.ext.sql.package-info Maven / Gradle / Ivy
/**
* == Vert.x Common SQL interface
*
* The common SQL interface is used to interact with Vert.x SQL services.
*
* You obtain a connection to the database via the service interface for the specific SQL service that
* you are using (e.g. JDBC/MySQL/PostgreSQL).
*
* To use this project, add the following dependency to the _dependencies_ section of your build descriptor:
*
* * Maven (in your `pom.xml`):
*
* [source,xml,subs="+attributes"]
* ----
*
* ${maven.groupId}
* ${maven.artifactId}
* ${maven.version}
*
* ----
*
* * Gradle (in your `build.gradle` file):
*
* [source,groovy,subs="+attributes"]
* ----
* compile '${maven.groupId}:${maven.artifactId}:${maven.version}'
* ----
*
* == Simple SQL Operations
*
* There are times when you will want to run a single SQL operation, e.g.: a single select of a row, or a update to a
* set of rows which do not require to be part of a transaction or have dependencies on the previous or next operation.
*
* For these cases, clients provide a boilerplate-less API {@link io.vertx.ext.sql.SQLOperations}. This interface will
* perform the following steps for you:
*
* 1. acquire a connection from the connection pool
* 2. perform your action
* 3. close and return the connection to the connection pool
*
* An example where users get loaded from the `USERS` table could be:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example16}
* ----
*
* You can perform the following operations as a simple one "shot" method call:
*
* * {@link io.vertx.ext.sql.SQLClient#query(java.lang.String, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#queryWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#querySingle(java.lang.String, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#querySingleWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#update(java.lang.String, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#updateWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#call(java.lang.String, io.vertx.core.Handler)}
* * {@link io.vertx.ext.sql.SQLClient#callWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}
*
* For further details on these API please refer to the {@link io.vertx.ext.sql.SQLOperations} interface.
*
*
* == The SQL Connection
*
* A connection to the database is represented by {@link io.vertx.ext.sql.SQLConnection}.
*
* === Auto-commit
*
* When you obtain a connection auto commit is set to `true`. This means that each operation you perform will effectively
* execute in its own transaction.
*
* If you wish to perform multiple operations in a single transaction you should set auto commit to false with
* {@link io.vertx.ext.sql.SQLConnection#setAutoCommit(boolean, io.vertx.core.Handler)}.
*
* When the operation is complete, the handler will be called:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example1}
* ----
*
* === Executing queries
*
* To execute a query use {@link io.vertx.ext.sql.SQLConnection#query(java.lang.String, io.vertx.core.Handler)}
*
* The query string is raw SQL that is passed through without changes to the actual database.
*
* The handler will be called with the results, represented by {@link io.vertx.ext.sql.ResultSet} when the query has
* been run.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example2}
* ----
*
* The {@link io.vertx.ext.sql.ResultSet} instance represents the results of a query.
*
* The list of column names are available with {@link io.vertx.ext.sql.ResultSet#getColumnNames()}, and the actual results
* available with {@link io.vertx.ext.sql.ResultSet#getResults()}
*
* The results are a list of {@link io.vertx.core.json.JsonArray} instances, one for each row of the results.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example3}
* ----
*
* You can also retrieve the rows as a list of Json object instances with {@link io.vertx.ext.sql.ResultSet#getRows()} -
* this can give you a somewhat simpler API to work with, but please be aware that SQL results can contain duplicate
* column names - if that's the case you should use {@link io.vertx.ext.sql.ResultSet#getResults()} instead.
*
* Here's an example of iterating through the results as Json object instances:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example3__1}
* ----
*
* === Prepared statement queries
*
* To execute a prepared statement query you can use
* {@link io.vertx.ext.sql.SQLConnection#queryWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}.
*
* This takes the query, containing the parameter place holders, and a {@link io.vertx.core.json.JsonArray} or parameter
* values.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example3_1}
* ----
*
* === Executing INSERT, UPDATE or DELETE
*
* To execute an operation which updates the database use {@link io.vertx.ext.sql.SQLConnection#update(java.lang.String, io.vertx.core.Handler)}.
*
* The update string is raw SQL that is passed through without changes to the actual database.
*
* The handler will be called with the results, represented by {@link io.vertx.ext.sql.UpdateResult} when the update has
* been run.
*
* The update result holds the number of rows updated with {@link io.vertx.ext.sql.UpdateResult#getUpdated()}, and
* if the update generated keys, they are available with {@link io.vertx.ext.sql.UpdateResult#getKeys()}.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example4}
* ----
*
* === Prepared statement updates
*
* To execute a prepared statement update you can use
* {@link io.vertx.ext.sql.SQLConnection#updateWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}.
*
* This takes the update, containing the parameter place holders, and a {@link io.vertx.core.json.JsonArray} or parameter
* values.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example5}
* ----
*
* === Callable statements
*
* To execute a callable statement (either SQL functions or SQL procedures) you can use
* {@link io.vertx.ext.sql.SQLConnection#callWithParams(java.lang.String, io.vertx.core.json.JsonArray, io.vertx.core.json.JsonArray, io.vertx.core.Handler)}.
*
* This takes the callable statement using the standard JDBC format `{ call func_proc_name() }`, optionally including
* parameter place holders e.g.: `{ call func_proc_name(?, ?) }`, a {@link io.vertx.core.json.JsonArray} containing the
* parameter values and finally a {@link io.vertx.core.json.JsonArray} containing the
* output types e.g.: `[null, 'VARCHAR']`.
*
* Note that the index of the output type is as important as the params array. If the return value is the second
* argument then the output array must contain a null value as the first element.
*
* A SQL function returns some output using the `return` keyword, and in this case one can call it like this:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example8}
* ----
*
* When working with Procedures you and still return values from your procedures via its arguments, in the case you do
* not return anything the usage is as follows:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example9}
* ----
*
* However you can also return values like this:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example10}
* ----
*
* Note that the index of the arguments matches the index of the `?` and that the output parameters expect to be a
* String describing the type you want to receive.
*
* To avoid ambiguation the implementations are expected to follow the following rules:
*
* * When a place holder in the `IN` array is `NOT NULL` it will be taken
* * When the `IN` value is NULL a check is performed on the OUT
* * When the `OUT` value is not null it will be registered as a output parameter
* * When the `OUT` is also null it is expected that the IN value is the `NULL` value.
*
* The registered `OUT` parameters will be available as an array in the result set under the output property.
*
* === Batch operations
*
* The SQL common interface also defines how to execute batch operations. There are 3 types of batch operations:
*
* * Batched statements {@link io.vertx.ext.sql.SQLConnection#batch(java.util.List, io.vertx.core.Handler)}
* * Batched prepared statements {@link io.vertx.ext.sql.SQLConnection#batchWithParams(java.lang.String, java.util.List, io.vertx.core.Handler)}
* * Batched callable statements {@link io.vertx.ext.sql.SQLConnection#batchCallableWithParams(java.lang.String, java.util.List, java.util.List, io.vertx.core.Handler)}
*
* A batches statement will exeucte a list of sql statements as for example:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example12}
* ----
*
* While a prepared or callable statement batch will reuse the sql statement and take an list of arguments as for example:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example11}
* ----
* === Executing other operations
*
* To execute any other database operation, e.g. a `CREATE TABLE` you can use
* {@link io.vertx.ext.sql.SQLConnection#execute(java.lang.String, io.vertx.core.Handler)}.
*
* The string is passed through without changes to the actual database. The handler is called when the operation
* is complete
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example6}
* ----
*
* === Multiple ResultSet responses
*
* In some cases your query might return more than one result set, in this case and to preserve the compatibility when
* the returned result set object is converted to pure json, the next result sets are chained to the current result set
* under the property `next`. A simple walk of all result sets can be achieved like this:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example13}
* ----
*
* === Streaming
*
* When dealing with large data sets, it is not advised to use API just described but to stream data since it avoids
* inflating the whole response into memory and JSON and data is just processed on a row by row basis, for example:
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example14}
* ----
*
* You still have full control on when the stream is pauses, resumed and ended. For cases where your query returns
* multiple result sets you should use the result set ended event to fetch the next one if available. If there is more
* data the stream handler will receive the new data, otherwise the end handler is invoked.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example15}
* ----
*
* === Using transactions
*
* To use transactions first set auto-commit to false with {@link io.vertx.ext.sql.SQLConnection#setAutoCommit(boolean, io.vertx.core.Handler)}.
*
* You then do your transactional operations and when you want to commit or rollback use
* {@link io.vertx.ext.sql.SQLConnection#commit(io.vertx.core.Handler)} or
* {@link io.vertx.ext.sql.SQLConnection#rollback(io.vertx.core.Handler)}.
*
* Once the commit/rollback is complete the handler will be called and the next transaction will be automatically started.
*
* [source,$lang]
* ----
* {@link examples.SQLExamples#example7}
* ----
*
* === Closing connections
*
* When you've done with the connection you should return it to the pool with {@link io.vertx.ext.sql.SQLConnection#close(io.vertx.core.Handler)}.
*
*/
@Document(fileName = "index.adoc")
@ModuleGen(name = "vertx-sql", groupPackage = "io.vertx")
package io.vertx.ext.sql;
import io.vertx.codegen.annotations.ModuleGen;
import io.vertx.docgen.Document;
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