[`length`][1] and [`dbms_lob.getlength`][2] return the number of characters when applied to a **CLOB** (Character LOB). When applied to a **BLOB** (Binary LOB), `dbms_lob.getlength` will return the number of bytes, which may differ from the number of characters in a multi-byte character set.

As the documentation doesn&#39;t specify what happens when you apply `length` on a BLOB, I would advise against using it in that case. If you want the number of bytes in a BLOB, use `dbms_lob.getlength`.


  [1]: http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/functions076.htm#i77725 &quot;LENGTH 10gR2&quot;
  [2]: http://docs.oracle.com/cd/B19306_01/appdev.102/b14258/d_lob.htm#i998484

On Android, I have a `WebView` that is displaying a page.

How do I get the page source without requesting the page again?

It seems `WebView` should have some kind of `getPageSource()` method that returns a string, but alas it does not.

If I enable JavaScript, what is the appropriate JavaScript to put in this call to get the contents?

    webview.loadUrl(&quot;javascript:(function() { &quot; +  
        &quot;document.getElementsByTagName(&#39;body&#39;)[0].style.color = &#39;red&#39;; &quot; +  
        &quot;})()&quot;);  




How do I get the web page contents from a WebView?

I&#39;m developing an app and don&#39;t have to ever worry about Internet&amp;nbsp;Explorer and was looking into some of the features present in A+ grade browsers that aren&#39;t in Internet&amp;nbsp;Explorer1.

One of these features I wanted to play around with is &lt;a href=&quot;https://developer.mozilla.org/en/New_in_JavaScript_1.7#let_definitions&quot; title=&quot;New in JavaScript 1.7 - MDC&quot;&gt;JavaScript&#39;s let keyword&lt;/a&gt;

I can&#39;t seem to get any of their &#39;let&#39; examples to work in Firefox 3.6 ([User-Agent][1] string: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6 (.NET CLR 3.5.30729)). I get `SyntaxError: missing ; before statement` when executing `let foo = &quot;bar&quot;`.

So, what browsers support the let keyword? (Or am I doing something wrong?)

  [1]: https://en.wikipedia.org/wiki/User_agent#Use_in_HTTP


What browsers currently support JavaScript&#39;s &#39;let&#39; keyword?

I&#39;m getting the same results from 

    select length(column_name) from table

as

`select dbms_lob.getlength(column_name) from table` 

However, the answers to
&lt;a href=&quot;https://stackoverflow.com/questions/840966/what-is-an-elegant-way-to-return-a-readable-file-size-of-a-file-stored-in-an-or&quot;&gt;this question&lt;/a&gt; seem to favor using `dbms_lob.getlength()`.  
  
Is there any benefit to using `dbms_lob.getlength()`? 

If it changes the answer, I know all of the blobs are .bmp images (never worked with blobs before).

dbms_lob.getlength() vs. length() to find blob size in oracle

I'm getting the same results from
<pre><code class="hljs language-sql">select length(column_name) from table
</code></pre>
as
<code>select dbms_lob.getlength(column_name) from table</code>
However, the answers to
<a 840966="" href="<a href=" https:="" stackoverflow.com="" questions="" what-is-an-elegant-way-to-return-a-readable-file-size-of-a-file-stored-in-an-or&#x26;quot;&#x26;gt;this&#x22;="">https://stackoverflow.com/questions/840966/what-is-an-elegant-way-to-return-a-readable-file-size-of-a-file-stored-in-an-or">this</a> question seem to favor using <code>dbms_lob.getlength()</code>.
Is there any benefit to using <code>dbms_lob.getlength()</code>?
If it changes the answer, I know all of the blobs are .bmp images (never worked with blobs before).

I have the following column specified in a database: decimal(5,2)

How does one interpret this?

According to the properties on the column as viewed in SQL Server Management studio I can see that it means: decimal(Numeric precision, Numeric scale).

What do precision and scale mean in real terms?

It would be easy to interpret this as a decimal with 5 digits and two decimals places...ie 12345.12

P.S. I&#39;ve been able to determine the correct answer from a colleague but had great difficulty finding an answer online. As such, I&#39;d like to have the question and answer documented here on stackoverflow for future reference.

How do I interpret precision and scale of a number in a database?

I have a general Java method with the following method signature:

    private static ResultSet runSQLResultSet(String sql, Object... queryParams)

It opens a connection, builds a `PreparedStatement` using the sql statement and the parameters in the `queryParams` variable length array, runs it, caches the `ResultSet` (in a `CachedRowSetImpl`), closes the connection, and returns the cached result set.

I have exception handling in the method that logs errors. I log the sql statement as part of the log since it&#39;s very helpful for debugging. My problem is that logging the String variable `sql` logs the template statement with ?&#39;s instead of actual values. I want to log the *actual* statement that was executed (or tried to execute).

So... Is there any way to get the actual SQL statement that will be run by a `PreparedStatement`? (*Without* building it myself. If I can&#39;t find a way to access the `PreparedStatement&#39;s` SQL, I&#39;ll probably end up building it myself in my `catch`es.)



How can I get the SQL of a PreparedStatement?

    SELECT airline, airports.icao_code, continent, country, province, city, website 
    
    FROM airlines 
    FULL OUTER JOIN airports ON airlines.iaco_code = airports.iaco_code
    FULL OUTER JOIN cities ON airports.city_id = cities.city_id
    FULL OUTER JOIN provinces ON cities.province_id = provinces.province_id
    FULL OUTER JOIN countries ON cities.country_id = countries.country_id
    FULL OUTER JOIN continents ON countries.continent_id = continents.continent_id

It says that 

&gt; You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near &#39;outer join `airports` on airlines.iaco_code = airports.iaco_code
full outer join&#39; at line 4

The syntax looks right to me. I&#39;ve never done a lot of joins before, but I need those columns in a table which is cross referenced by various id&#39;s.

Why does MySQL report a syntax error on FULL OUTER JOIN?

I&#39;m trying to retrieve records from table by knowing the date in column contains date and time.

Suppose I have table called `t1` which contains only two column `name` and `date` respectively.

The data stored in column date like this `8/3/2010 12:34:20 PM`.

I want to retrieve this record by this query for example (note I don&#39;t put the time):

    Select * From t1 Where date=&quot;8/3/2010&quot;

This query give me nothing ! 

How can I retrieve `date` by knowing only `date` without the time?

Select from table by knowing only date without time (ORACLE)

I use an API that expects a SQL string. I take a user input, escape it and pass it along to the API.  The user input is quite simple. It asks for column values. Like so:

    string name = userInput.Value;

Then I construct a SQL query:

    string sql = string.Format(&quot;SELECT * FROM SOME_TABLE WHERE Name = &#39;{0}&#39;&quot;,
                               name.replace(&quot;&#39;&quot;, &quot;&#39;&#39;&quot;));

Is this safe enough? If it isn&#39;t, is there a simple library function that make column values safe:

    string sql = string.Format(&quot;SELECT * FROM SOME_TABLE WHERE Name = &#39;{0}&#39;&quot;,
                               SqlSafeColumnValue(name));


The API uses SQLServer as the database. 


How to escape simple SQL queries in C# for SqlServer

I have a query which works fine in MySQL, but when I run it on Oracle I get the following error:

&gt; SQL Error: ORA-00933: SQL command not properly ended&lt;br/&gt;
&gt; 00933. 00000 -  &quot;SQL command not properly ended&quot;

The query is:

    UPDATE table1
    INNER JOIN table2 ON table1.value = table2.DESC
    SET table1.value = table2.CODE
    WHERE table1.UPDATETYPE=&#39;blah&#39;;

Update statement with inner join on Oracle

I have an big problem with an SQL Statement in Oracle. I want to select the TOP 10 Records ordered by STORAGE_DB which aren&#39;t in a list from an other select statement.

This one works fine for all records:

    SELECT DISTINCT 
      APP_ID, 
      NAME, 
      STORAGE_GB, 
      HISTORY_CREATED, 
      TO_CHAR(HISTORY_DATE, &#39;DD.MM.YYYY&#39;) AS HISTORY_DATE  
      FROM HISTORY WHERE 
          STORAGE_GB IS NOT NULL AND 
            APP_ID NOT IN (SELECT APP_ID
                           FROM HISTORY
                            WHERE TO_CHAR(HISTORY_DATE, &#39;DD.MM.YYYY&#39;) = &#39;06.02.2009&#39;) 
            
But when I am adding 

    AND ROWNUM &lt;= 10
    ORDER BY STORAGE_GB DESC

I&#39;m getting some kind of &quot;random&quot; Records. I think because the limit takes in place before the order.

Does someone has an good solution? The other problem: This query is realy slow (10k+ records)


Oracle SELECT TOP 10 records

I have a database which has a NOT NULL constraint on a field, and I want to remove this constraint.  The complicating factor is that this constraint has a system-defined name, and that constraint&#39;s name differs between the production server, integration server, and the various developer databases.  Our current process is to check in change scripts, and an automated task executes the appropriate queries through sqlplus against the target database, so I&#39;d prefer a solution that could just be sent straight into sqlplus.

On my own database, the SQL to drop this would be:

    alter table MYTABLE drop constraint SYS_C0044566

I can see the constraint when I query the `all_constraints` view:

    select * from all_constraints where table_name = &#39;MYTABLE&#39;

but I am not sure how to work with the `SEARCH_CONDITION`&#39;s `LONG` data type or how best to dynamically delete the looked-up constraint even after I know its name.

So, how can I create a change script that can drop this constraint based on what it is, rather than what its name is?

----
EDIT:
@Allan&#39;s answer is a good one, but I am concerned (in my lack of Oracle expertise) that it may not be universally true that any constraint that might have a system-generated name will have associated with it a way to remove the constraint without having to know its name.  Is it true that there will always be a way to avoid having to know a system-named constraint&#39;s name when logically dropping that constraint?

How can I drop a &quot;not null&quot; constraint in Oracle when I don&#39;t know the name of the constraint?

How to export Oracle DB data using SQL Developer? I need all data, tables, constraints, structure and so on.

How to export data with Oracle SQL Developer?

I&#39;m looking for a command line wrapper for the DEFLATE algorithm.

I have a file (git blob) that is compressed using DEFLATE, and I want to uncompress it. The gzip command does not seem to have an option to directly use the DEFLATE algorithm, rather than the gzip format.

Ideally I&#39;m looking for a standard Unix/Linux tool that can do this.

edit: This is the output I get when trying to use gzip for my problem:

    $ cat .git/objects/c0/fb67ab3fda7909000da003f4b2ce50a53f43e7 | gunzip
    
    gzip: stdin: not in gzip format



How to DEFLATE with a command line tool to extract a git object?

I&#39;ve got some `byte[]` fields in my entities, e.g.:

    @Entity
    public class ServicePicture implements Serializable {
    	private static final long serialVersionUID = 2877629751219730559L;
    	// seam-gen attributes (you should probably edit these)
    	@Id
    	@GeneratedValue
    	private Long id;
    	private String description;
    
    	@Lob
    	@Basic(fetch = FetchType.LAZY)
    	private byte[] picture;

On my database schema the field is set to `BLOB` so this should be fine. Anyway: Everytime when I try to insert a picture or pdf - nothing bigger than `1mb`, I only recieve this

    16:52:27,327 WARN  [JDBCExceptionReporter] SQL Error: 0, SQLState: 22001
    16:52:27,327 ERROR [JDBCExceptionReporter] Data truncation: Data too long for column &#39;picture&#39; at row 1
    16:52:27,328 ERROR [STDERR] javax.persistence.PersistenceException: org.hibernate.exception.DataException: could not insert: [de.ac.dmg.productfinder.entity.ServicePicture]
    16:52:27,328 ERROR [STDERR] 	at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629)
    16:52:27,328 ERROR [STDERR] 	at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:218)
    16:52:27,328 ERROR [STDERR] 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    16:52:27,328 ERROR [STDERR] 	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    16:52:27,328 ERROR [STDERR] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    16:52:27,328 ERROR [STDERR] 	at java.lang.reflect.Method.invoke(Unknown Source)
    16:52:27,328 ERROR [STDERR] 	at org.jboss.seam.persistence.EntityManagerInvocationHandler.invoke(EntityManagerInvocationHandler.java:46)
    16:52:27,328 ERROR [STDERR] 	at $Proxy142.persist(Unknown Source)

I&#39;ve checked my MySQL cnf and the `max_allowed`param is set to `16M` - am I missing something?

JPA, Mysql Blob returns data too long

I have an application using hibernate 3.1 and JPA annotations.  It has a few objects with byte[] attributes (1k - 200k in size).  It uses the JPA @Lob annotation, and hibernate 3.1 can read these just fine on all major databases -- it seems to hide the JDBC Blob vendor peculiarities (as it should do).

    @Entity
    public class ConfigAttribute {
      @Lob
      public byte[] getValueBuffer() {
        return m_valueBuffer;
      }
    }

We had to upgrade to 3.5, when we discovered that hibernate 3.5  [breaks (and won&#39;t fix)][1] this annotation combination in postgresql (with no workaround).  I have not found a clear fix so far, but I did notice that if I just remove the @Lob, it uses the postgresql type bytea (which works, but only on postgres).

    annotation                   postgres     oracle      works on
    -------------------------------------------------------------
    byte[] + @Lob                oid          blob        oracle
    byte[]                       bytea        raw(255)    postgresql
    byte[] + @Type(PBA)          oid          blob        oracle
    byte[] + @Type(BT)           bytea        blob        postgresql
    
    once you use @Type, @Lob seems to not be relevant
    note: oracle seems to have deprecated the &quot;raw&quot; type since 8i.

I am looking for a way to have a single annotated class (with a blob property) which is portable across major databases.

 - What is the portable way to annotate a byte[] property?
 - Is this fixed in some recent version of hibernate?

**Update:**
After reading [this blog][2] I have finally figured out what the original workaround in the JIRA issue was: Apparently you are supposed to drop @Lob and annotate the property as:

    @Type(type=&quot;org.hibernate.type.PrimitiveByteArrayBlobType&quot;) 
    byte[] getValueBuffer() {...

However, this does not work _for me_ -- I still get OIDs instead of bytea; it did however work for the author of the JIRA issue, who seemed to want oid.

After the answer from A. Garcia, I then tried this combo, which actually does work on postgresql, but not on oracle.

    @Type(type=&quot;org.hibernate.type.BinaryType&quot;) 
    byte[] getValueBuffer() {...

What I really need to do is control which @org.hibernate.annotations.Type the combination (@Lob + byte[] gets mapped) to (on postgresql).

----------

Here is the snippet from 3.5.5.Final from MaterializedBlobType (sql type Blob).  According to Steve&#39;s blog, postgresql wants you to use Streams for bytea (don&#39;t ask me why) and postgresql&#39;s custom Blob type for oids.  Note also that using setBytes() on JDBC is also for bytea (from past experience).  So this explains why use-streams has no affect they both assume &#39;bytea&#39;.

    public void set(PreparedStatement st, Object value, int index) {
     byte[] internalValue = toInternalFormat( value );
     if ( Environment.useStreamsForBinary() ) {
      // use streams = true
       st.setBinaryStream( index, 
        new ByteArrayInputStream( internalValue ), internalValue.length );
     }
     else {
      // use streams = false
      st.setBytes( index, internalValue );
     }
    }

This results in:

    ERROR: column &quot;signature&quot; is of type oid but expression is of type bytea

**Update**
The next logical question is: &quot;why not just change the table definitions manually to bytea&quot; and keep the (@Lob + byte[])?  This _does_ work, **UNTIL** you try to store a null byte[].  Which the postgreSQL driver thinks is an OID type expression and the column type is bytea -- this is because hibernate (rightly) calls JDBC.setNull() instead of JDBC.setBytes(null) which PG driver expects. 

    ERROR: column &quot;signature&quot; is of type bytea but expression is of type oid

The type system in hibernate is currently a &#39;work in progress&#39; (according to 3.5.5 deprecation comment).  In fact so much of the 3.5.5 code is deprecated, it is hard to know what to look at when sub-classing the PostgreSQLDialect).  

AFAKT, Types.BLOB/&#39;oid&#39; on postgresql should be mapped to some custom type which uses OID style JDBC access (i.e. PostgresqlBlobType object and NOT MaterializedBlobType).  I&#39;ve never actually successfully used Blobs with postgresql, but I do know that bytea just simply works as one / I would expect.

I am currently looking at the BatchUpdateException -- its possible that the driver doesn&#39;t support batching.  

----------
Great quote from 2004:
 &quot;To sum up my ramblings, I&#39;d say they we should wait for the JDBC driver to do LOBs properly before changing Hibernate.&quot;


**References:**

 - https://forum.hibernate.org/viewtopic.php?p=2393203
 - https://forum.hibernate.org/viewtopic.php?p=2435174
 - http://hibernate.atlassian.net/browse/HHH-4617
 - http://postgresql.1045698.n5.nabble.com/Migration-to-Hibernate-3-5-final-td2175339.html
 - https://jira.springframework.org/browse/SPR-2318
 - https://forums.hibernate.org/viewtopic.php?p=2203382&amp;sid=b526a17d9cf60a80f13d40cf8082aafd
 - http://virgo47.wordpress.com/2008/06/13/jpa-postgresql-and-bytea-vs-oid-type/

  [1]: http://hibernate.atlassian.net/browse/HHH-4876
  [2]: http://in.relation.to/Bloggers/PostgreSQLAndBLOBs#comment15505



proper hibernate annotation for byte[]

I&#39;m trying to implement Git to manage creative assets (Photoshop, Illustrator, Maya, etc.), and I&#39;d like to exclude files from Git based on file size rather than extension, location, etc.

For example, I don&#39;t want to exclude all .avi files, but there are a handful of massive +1GB avi files in random directories that I don&#39;t want to commit. 

Any suggestions?

gitignore by file size?

 - What is it a BLOB?
 - How can I use it?
 - What are the differences between DBMS&#39;s BLOBs. I would like to save data using BLOBs into any DBMS and then read that BLOB with a library.



Content Type	Original Author	Original Content on Stackoverflow
Question	user285498	View Question on Stackoverflow
Solution 1 - Sql	Vincent Malgrat	View Answer on Stackoverflow

dbms_lob.getlength() vs. length() to find blob size in oracle

Sql Problem Overview

Sql Solutions

Solution 1 - Sql

What browsers currently support JavaScript's 'let' keyword?

How do I get the web page contents from a WebView?

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