The driverquery command enables an administrator to display a list of installed device drivers.

Availability

Driverquery is an external command and is available for the following Microsoft operating systems.

Drivers Syntax Definition

Driverquery syntax

• Supports JDK15, JDK14, JDK13, JDK12, JDK11, JDK10, JDK9, JDK8 and compliant to JDBC 4.3 and JDBC 4.2 by JDBC driver (ojdbc11.jar (21c only), ojdbc10.jar (19c only) and ojdbc8.jar) and Universal Connection Pool (ucp.jar). JDBC Reactive Extensions - A set of methods that extend the JDBC standard to offer asynchronous database access.
• A 'Driver class' is often just the class that contains a main. In a real project, you may often have numerous 'Driver classes' for testing and whatnot, or you can build a main into any of your objects and select the runnable class through your IDE, or by simply specifying 'java classname.'

Driverquery examples

Alibaba AnalyticDB for MySQL uses MySQL drivers. If you don't have the MySQL driver installed, you can get it from the MySQL website. We recommend that you install the latest MySQL 8.0 driver.

Displays the list of device drivers on the computer similar to the example output below.

Syntax Drivers

In the previous lesson we talk about the transaction. A transaction is a couple value/time that is scheduled on a signal.

The set of transactions for a signal is the driver of that signal.

In its turn, the driver is driven by the source of the signal.

The source of a signal is a

• process that assigns values to the signal
• connection of the signal to a port of type in, inout , or buffer.

A signal can have either a single source or multiple sources; therefore, one or more drivers.

In the case of more than one driver, the signal must be of a “resolved type” and a resolution function must be associated with it: this function must “resolve” the drivers into a single transaction.

It is illegal to have multiple drivers for a signal, which is not a resolved type, that is, a signal for which the bus resolution function is not defined.

Driver example

Here there are some examples of driver and source.

Example 1

This should clarify the concept: when we introduced the process statement, in the example we talk about driving the output port of the entity. In the driver definition, we stated that a process is a driver for the signal. In this case, the process is a driver for signal “a”. The statement is OK.

Example 2

…

the assignment on signal “a” seems to be the same of previous one but two different processes execute the task. This is an example of multiple drivers: as we state, the process is a driver for the signal. This code is illegal since the signal “a” is a not resolved type.

In fact integer type is not resolved type as we will see going ahead. In this case, the simulator will rise a compile error. If “a” have a resolution function, the simulator will compile the code. The code syntax is correct but, in layout phase, the analyzer will rise a multiple drive error.

Example 3

This example is a concurrent assignment of signal “a” in the statement section. Also in this case, “a” has single driver. This situation is very similar to the Example 1.

Also in this example, “a” has two drivers that are represented by the two concurrent assignment.

Concurrent Assignment: Bad Driver Example

Let’s design a 4-way mux similar to the example seen in the previous lesson. In this case the mux selector is bit-vector that means is a bus of 2 bit instead of two different lines s0 and s1.

An incorrect way to describe the mux is:

It is clear that this implementation create 4 different drivers for output “e”. In this case, the simulator will rise a “multiple drive error” on signal “e” and stop compiling. Being more precise, the simulator stops because the type bit-vector is a no-resolved type. Having a multiple driver on a signal is not a syntax error.

Drivers Synaptics Touchpad

Concurrent Assignment: Good Driver Example

Drivers Synonym

Better and canonical implementation of a 4-way mux is:

Drivers Synonym As Verb

In this case, only one driver is present for signal “e”. In fact, the conditional assignment is only one.

As rule of thumb, in a concurrent statement, each assignment is a driver for the assigned signal.

Selenium Driver Syntax

As we will see, this is not true in the sequential statement.

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