`SYSDATE` is an Oracle only function.

The ANSI standard defines `current_date` or `current_timestamp` which **is** supported by Postgres and documented in the manual:&lt;br/&gt;
http://www.postgresql.org/docs/current/static/functions-datetime.html#FUNCTIONS-DATETIME-CURRENT

(Btw: Oracle supports `CURRENT_TIMESTAMP` as well)

You should pay attention to the difference between `current_timestamp`, `statement_timestamp()` and `clock_timestamp()` (which is explained in the manual, see the above link)

---

The part `where up_time like sysdate` does not make *any* sense at all. Neither in Oracle nor in Postgres. If you want to get rows from &quot;today&quot;, you need something like:

    select up_time 
    from exam 
    where up_time = current_date

Note that in Oracle you would probably want `trunc(up_time) = trunc(sysdate)` to get rid of the time part that is always included in Oracle.



**NOW()** is the replacement of Oracle Sysdate in Postgres.

Try &quot;***Select now()***&quot;, it will give you the system timestamp.



**The following functions are available to obtain the current date and/or time in PostgreSQL**:

    CURRENT_TIME
    
    CURRENT_DATE
    
    CURRENT_TIMESTAMP

*Example*

    SELECT CURRENT_TIME;
    08:05:18.864750+05:30
    
    SELECT CURRENT_DATE;
    2020-05-14
    
    SELECT CURRENT_TIMESTAMP;
    2020-05-14 08:04:51.290498+05:30

[postgresql docs ][1]

  [1]: https://www.postgresql.org/docs/current/functions-datetime.html

You may want to use **statement_timestamp()**. This give the timestamp when the statement was executed. Whereas `NOW()` and `CURRENT_TIMESTAMP` give the timestamp when the transaction started.

More details in [the manual][1] 


  [1]: https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-CURRENT

I am testing the speed of getting data from Dictionary VS list. 
&lt;br&gt;I&#39;ve used this code to test : 

        internal class Program
    {
        private static void Main(string[] args)
        {
            var stopwatch = new Stopwatch();
            List&lt;Grade&gt; grades = Grade.GetData().ToList();
            List&lt;Student&gt; students = Student.GetStudents().ToList();

            stopwatch.Start();
            foreach (Student student in students)
            {
                student.Grade = grades.Single(x =&gt; x.StudentId == student.Id).Value;
            }
            stopwatch.Stop();
            Console.WriteLine(&quot;Using list {0}&quot;, stopwatch.Elapsed);
            stopwatch.Reset();
            students = Student.GetStudents().ToList();
            stopwatch.Start();
            Dictionary&lt;Guid, string&gt; dic = Grade.GetData().ToDictionary(x =&gt; x.StudentId, x =&gt; x.Value);
            foreach (Student student in students)
            {
                student.Grade = dic[student.Id];
            }
            stopwatch.Stop();
            Console.WriteLine(&quot;Using dictionary {0}&quot;, stopwatch.Elapsed);
            Console.ReadKey();
        }
    }

    public class GuidHelper
    {
        public static List&lt;Guid&gt; ListOfIds=new List&lt;Guid&gt;();

        static GuidHelper()
        {
            for (int i = 0; i &lt; 10000; i++)
            {
                ListOfIds.Add(Guid.NewGuid());
            }
        }
    }


    public class Grade
    {
        public Guid StudentId { get; set; }
        public string Value { get; set; }

        public static IEnumerable&lt;Grade&gt; GetData()
        {
            for (int i = 0; i &lt; 10000; i++)
            {
                yield return new Grade
                                 {
                                     StudentId = GuidHelper.ListOfIds[i], Value = &quot;Value &quot; + i
                                 };
            }
        }
    }

    public class Student
    {
        public Guid Id { get; set; }
        public string Name { get; set; }
        public string Grade { get; set; }

        public static IEnumerable&lt;Student&gt; GetStudents()
        {
            for (int i = 0; i &lt; 10000; i++)
            {
                yield return new Student
                                 {
                                     Id = GuidHelper.ListOfIds[i],
                                     Name = &quot;Name &quot; + i
                                 };
            }
        }
    }
There is list of students and grades in memory they have StudentId in common. &lt;br&gt;
In first way I tried to find Grade of a student using LINQ on a list that takes near 7 seconds on my machine and in another way first I converted List into dictionary then finding grades of student from dictionary using key that takes less than a second . 
![enter image description here][1]


  [1]: http://i.stack.imgur.com/LTzMW.png

Why is dictionary so much faster than list?

Why can&#39;t you use a trailing comma with `*args` in Python?  In other words, this works

    &gt;&gt;&gt; f(1, 2, b=4,)

But this does not

    &gt;&gt;&gt; f(*(1, 2), b=4,)
      File &quot;&lt;stdin&gt;&quot;, line 1
        f(*(1, 2), b=4,)
                       ^
    SyntaxError: invalid syntax

This is the case with both Python 2 and Python 3.

Why is a trailing comma a SyntaxError in an argument list that uses *args syntax?

I want to perform a query using sysdate like:

    select up_time from exam where up_time like sysdate

which is possible in Oracle.

However, it seems that PostgreSQL doesn&#39;t support sysdate. I couldn&#39;t find sysdate in postgres documentation. What is the replacement for sysdate in PostgreSQL?

What is PostgreSQL equivalent of SYSDATE from Oracle?

I want to perform a query using sysdate like:
<pre><code class="hljs language-sql">select up_time from exam where up_time like sysdate
</code></pre>
which is possible in Oracle.
However, it seems that PostgreSQL doesn't support sysdate. I couldn't find sysdate in postgres documentation. What is the replacement for sysdate in PostgreSQL?

I&#39;m developing a very simple application which I intend to use to troubleshoot an issue I am having on a few machines but before I even got that far I ran into a few issues, including cpu architecture differences and Oracle database libraries.

I have a database server listed in `tnsnames.ora`, sitting in my `C:\oracle\11g\network\admin` directory. If I tnsping this server I get the desired response. If I code my C# program to connect to this server with the following code using Oracle.DataAccess.Client, it works.

    string connectionString = &quot;Data Source=DSDSDS;User Id=UNUNUN;Password=PWPWPW;&quot;;
    DataTable dataTable = new DataTable();

    using (var connection = new OracleConnection(connectionString)) {
        connection.Open();
        using (var command = new OracleCommand()) {
            command.Connection = connection;
            command.CommandText = sql;
            command.CommandType = CommandType.Text;
            using (var oda = new OracleDataAdapter(command)) {
                oda.Fill(dataTable);
            }
        }
    }

However Oracle.DataAccess is dependent on the architecture of the system it runs on. I saw that there is another library Oracle.ManagedDataAccess which is architecture independent. When I use this library it no longer is able to connect to the server. An `ORA-12545: Network Transport: Unable to resolve connect hostname` is thrown.

Why is this the case? What is different between these two libraries because based upon what I&#39;ve read thus far this shouldn&#39;t be an issue.

Extra information:

 - %ORACLE_HOME% and %TNS_ADMIN% are NOT defined (remember that tnsping and Oracle.DataAccess work)
 - PATH has `C:\oracle\11g\BIN` defined.
 - My machine only has one `tnsnames.ora` file

If I move tnsnames.ora to the same location as my .exe file, it works. Why can Oracle.DataAccess find tnsnames.ora in the `C:\oracle\11g\network\admin` directory but Oracle.ManagedAccess cannot?

Why would Oracle.ManagedDataAccess not work when Oracle.DataAccess does?

After executing this SQL in oracle 10g:

    SELECT SYSDATE, CURRENT_TIMESTAMP  FROM DUAL
I receive this strange output:
![Toad output for query][1]


  [1]: http://i.stack.imgur.com/FiPgB.png

What is cause of the difference in time? 
The server time is equal of SYSDATE value

Different CURRENT_TIMESTAMP and SYSDATE in oracle

How can I do in **one select** with multiple columns and put each column in a variable?

Something like this:



    --code here
    V_DATE1 T1.DATE1%TYPE;
    V_DATE2 T1.DATE2%TYPE;
    V_DATE3 T1.DATE3%TYPE;
    
    SELECT T1.DATE1 INTO V_DATE1, T1.DATE2 INTO V_DATE2, T1.DATE3 INTO V_DATE3
    FROM T1
    WHERE ID=&#39;X&#39;;

    --code here


Select multiple columns into multiple variables

I have installed Oracle 11g Express Edition Release 2 in my windows 7 64 bit OS and tried to execute JDBC program, then I got the following error:

    java.sql.SQLException: Listener refused the connection with the following error:
    ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)
        at oracle.jdbc.driver.PhysicalConnection.&lt;init&gt;(PhysicalConnection.java:531)
        at oracle.jdbc.driver.T4CConnection.&lt;init&gt;(T4CConnection.java:221)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at com.jlcindia.jdbc.JDBCUtil.geOracleConnection(JDBCUtil.java:28)
        at Lab3O.main(Lab3O.java:15)
    Caused by: oracle.net.ns.NetException: Listener refused the connection with the following error:
    ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
        at oracle.net.ns.NSProtocol.connect(NSProtocol.java:385)
        at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
        ... 8 more

ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

I have a problem with committing changes in LinqPad. I am using Oracle database over IQ driver in LinqPad. I can retrieve data but I don&#39;t know how to submit changes to database. 

I retrieve data from database:
 
     var items = Asyncqueue.Where(x =&gt; ids.Any(y=&gt; y == x.Asyncqueueid));
     // then I have to fix data 

I have tried to set submit action like this:
  
     Asyncqueue.SetSubmitAction(items, SubmitAction.Update);





 

How to submit changes in LinqPad

I&#39;m trying to set up Postgres for the first time, and I need to create a user with permissions to read and create databases. However, when I use:

```
createuser username
```
in my terminal I get the following message: 

&gt; createuser: could not connect to database postgres: FATAL:  role &quot;tom&quot; does not exist

Tom is my Ubuntu user account that I&#39;m logged into right now. I&#39;m trying to create a username of &quot;postgres&quot; then do a `psql -U psql template1` so I can create a database and assign an owner to it for my Rails app. 

Createuser: could not connect to database postgres: FATAL: role &quot;tom&quot; does not exist

I have a database that was exported with pg_dump, but now when I&#39;m trying to import it again with:

    psql -d databasename &lt; mydump.sql

It fails trying to grant roles to people that don&#39;t exist. (error says &#39;Role &quot;xxx&quot; does not exist&#39;) 

Is there a way to import and set all the roles automatically to my user?

Import postgres database without roles

I have DB &quot;test&quot; in PostgreSql. I want to write sql to get owner my database.

Get DB owner&#39;s name in PostgreSql

A very frequently asked question here is how to do an upsert, which is what MySQL calls `INSERT ... ON DUPLICATE UPDATE` and the standard supports as part of the `MERGE` operation.

Given that PostgreSQL doesn&#39;t support it directly (before pg 9.5), how do you do this? Consider the following:

    CREATE TABLE testtable (
        id integer PRIMARY KEY,
        somedata text NOT NULL
    );
    
    INSERT INTO testtable (id, somedata) VALUES
    (1, &#39;fred&#39;),
    (2, &#39;bob&#39;);

Now imagine that you want to &quot;upsert&quot; the tuples `(2, &#39;Joe&#39;)`, `(3, &#39;Alan&#39;)`, so the new table contents would be:

    (1, &#39;fred&#39;),
    (2, &#39;Joe&#39;),    -- Changed value of existing tuple
    (3, &#39;Alan&#39;)    -- Added new tuple

That&#39;s what people are talking about when discussing an `upsert`. Crucially, any approach must be *safe in the presence of multiple transactions working on the same table* - either by using explicit locking, or otherwise defending against the resulting race conditions.

This topic is discussed extensively at https://stackoverflow.com/q/1109061/398670, but that&#39;s about alternatives to the MySQL syntax, and it&#39;s grown a fair bit of unrelated detail over time. I&#39;m working on definitive answers.

These techniques are also useful for &quot;insert if not exists, otherwise do nothing&quot;, i.e. &quot;insert ... on duplicate key ignore&quot;.

How to UPSERT (MERGE, INSERT ... ON DUPLICATE UPDATE) in PostgreSQL?

I&#39;m trying to create a Postgres database for the first time.

I assigned basic read-only permissions to the DB role that must access the database from my PHP scripts, and I have a curiosity: If I execute

    GRANT some_or_all_privileges ON ALL TABLES IN SCHEMA schema TO role;

is there any need to also execute this?

    GRANT USAGE ON SCHEMA schema TO role;

From the [documentation][1]:

&gt; USAGE: For schemas, allows access to objects contained in the
&gt; specified schema (assuming that the objects&#39; own privilege
&gt; requirements are also met). Essentially this allows the grantee to
&gt; &quot;look up&quot; objects within the schema.

I think that if I can select or manipulate any data contained in the schema, I can access to any objects of the schema itself. Am I wrong? If not, what is `GRANT USAGE ON SCHEMA` used for? And what does the documentation mean exactly with &quot;assuming that the objects&#39; own privilege requirements are also met&quot;?

  [1]: http://www.postgresql.org/docs/9.1/static/sql-grant.html

Content Type	Original Author	Original Content on Stackoverflow
Question	user2365917	View Question on Stackoverflow
Solution 1 - Oracle	a_horse_with_no_name	View Answer on Stackoverflow
Solution 2 - Oracle	Virendra Patel	View Answer on Stackoverflow
Solution 3 - Oracle	abhinav kumar	View Answer on Stackoverflow
Solution 4 - Oracle	segfault	View Answer on Stackoverflow

What is PostgreSQL equivalent of SYSDATE from Oracle?

Oracle Problem Overview

Oracle Solutions

Solution 1 - Oracle

Solution 2 - Oracle

Solution 3 - Oracle

Solution 4 - Oracle

Why is a trailing comma a SyntaxError in an argument list that uses *args syntax?

Why is dictionary so much faster than list?

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