Hbase shell Filter with Prefix - nosql

I have to get all the entries from a HBASE table which have values substring of the given input.
For example if my table is like below:
Table | Family | ColumnQualifier | Value
exp | family | column | 1000xyz
exp | family | column1 | 1000abc
exp | family | column2 | 1001abc
I need to get the entries 1000xyz and 1000abc by value filter with input - 1000
I tried the value filter :
scan 'exp', { FILTER => "ValueFilter( =, 'binary:1000')" }
which gives me the exact value 1000.
Thanks in advance!!!!

Use binaryprefix instead of binary as value comparator,
scan 'exp', { FILTER => "ValueFilter( =, 'binaryprefix:1000' )" }

Related

pyspark column type casting in pivot

I have a dataframe where I want to create pivot table from 2 columns, i'm using the question header column which will have its value pivoted like below : age , age_numeric
and the answer header is the value , my problem is I want to put the value of the answer header in a list which I'm doing using collect_list function, but the problem is i want the new column like age_numeric to be list of int, while column age to be list of strings, based on question type column, but when i try the code it always gives me a list of strings, any idea how to solve this problem?
this is the code
y=output.groupby("sessionId").pivot("questionHeader").
agg(collect_list(when(col("questionType")=="numericAnswer",
col("answerHeader")
.cast("float")).when(col("questionType")!="numericAnswer",col("answerHeader"))))
this is what i get
| session id | Age | Age_numeric
| 1 | ["20-25 years"] | ["20"]
| 3 | ["20-25 years"] | ["20"]
This is what i want
| session id | Age | Age_numeric
| 1 | ["20-25 years"] | [20]
| 3 | ["20-25 years"] | [20]
If you want the output as in the last two rows, then you do not require a pivot, just groupby and collect_list on each of the two columns To get the list of integers for Age_numeric, apply .cast("array< int>"), or change the type of Age_numeric column before collect_list().
Replicate the data
import pyspark.sql.functions as F
data = [(1, "20-25 years", "20"), (3, "20-25 years", "20")]
df = spark.createDataFrame(data, schema=["session_id", "Age", "Age_numeric"])
Replicate the output
df_out = (df.groupBy("session_id")
.agg(F.collect_list("Age").alias("Age"),
F.collect_list("Age_numeric")
.cast("array<int>")
.alias("Age_numeric"))

Postgresql - Filter object array and extract required values in a json object

I have a PostgreSQL table like below:
| data |
| -------------- |
| {"name":"a","tag":[{"type":"country","value":"US"}]} |
| {"name":"b","tag":[{"type":"country","value":"US"}]}, {"type":"country","value":"UK"}]} |
| {"name":"c","tag":[{"type":"gender","value":"male"}]} |
The goal is to extract all the value in "tag" array with "type" = "country" and aggregate them into a text array. The expected result is as follows:
| result |
| -------------- |
| ["US"] |
| ["US", "UK"] |
| [] |
I've tried to expand the "tag" array and aggregate the desired result back; however, it requires a unique id to group up the results. Hence, I add a column with row number to serve as unique id. Here is what I've done:
SELECT ROW_NUMBER() OVER () AS id, * INTO data_table_with_id FROM data_table;
SELECT ARRAY_AGG(tag_value) AS result
FROM (
SELECT
id,
json_array_elements("data"::json->'tag')->>'type' as tag_type,
json_array_elements("data"::json->'tag')->>'value' as tag_value
FROM data_table_with_id
) tags
WHERE tag_type = 'country'
GROUP BY id;
Is it possible to use a single select to filter the object array and get the required results?
You can do this easily with a JSON path function:
select jsonb_path_query_array(data, '$.tag[*] ?(#.type == "country").value')
from data_table;

Spark Scala Dataframe - replace/join column values with values from another dataframe (but is transposed)

I have a table with ~300 columns filled with characters (stored as String):
valuesDF:
| FavouriteBeer | FavouriteCheese | ...
|---------------|-----------------|--------
| U | C | ...
| U | E | ...
| I | B | ...
| C | U | ...
| ... | ... | ...
I have a Data Summary, which maps the characters onto their actual meaning. It is in this form:
summaryDF:
| Field | Value | ValueDesc |
|------------------|-------|---------------|
| FavouriteBeer | U | Unknown |
| FavouriteBeer | C | Carlsberg |
| FavouriteBeer | I | InnisAndGunn |
| FavouriteBeer | D | DoomBar |
| FavouriteCheese | C | Cheddar |
| FavouriteCheese | E | Emmental |
| FavouriteCheese | B | Brie |
| FavouriteCheese | U | Unknown |
| ... | ... | ... |
I want to programmatically replace the character values of each column in valuesDF with the Value Descriptions from summaryDF. This is the result I'm looking for:
finalDF:
| FavouriteBeer | FavouriteCheese | ...
|---------------|-----------------|--------
| Unknown | Cheddar | ...
| Unknown | Emmental | ...
| InnisAndGunn | Brie | ...
| Carlsberg | Unknown | ...
| ... | ... | ...
As there are ~300 columns, I'm not keen to type out withColumn methods for each one.
Unfortunately I'm a bit of a novice when it comes to programming for Spark, although I've picked up enough to get by over the last 2 months.
What I'm pretty sure I need to do is something along the lines of:
valuesDF.columns.foreach { col => ...... } to iterate over each column
Filter summaryDF on Field using col String value
Left join summaryDF onto valuesDF based on current column
withColumn to replace the original character code column from valuesDF with new description column
Assign new DF as a var
Continue loop
However, trying this gave me Cartesian product error (I made sure to define the join as "left").
I tried and failed to pivot summaryDF (as there are no aggregations to do??) then join both dataframes together.
This is the sort of thing I've tried, and always getting a NullPointerException. I know this is really not the right way to do this, and can see why I'm getting Null Pointer... but I'm really stuck and reverting back to old, silly & bad Python habits in desperation.
var valuesDF = sourceDF
// I converted summaryDF to a broadcasted RDD
// because its small and a "constant" lookup table
summaryBroadcast
.value
.foreach{ x =>
// searchValue = Value (e.g. `U`),
// replaceValue = ValueDescription (e.g. `Unknown`),
val field = x(0).toString
val searchValue = x(1).toString
val replaceValue = x(2).toString
// error catching as summary data does not exactly mapping onto field names
// the joys of business people working in Excel...
try {
// I'm using regexp_replace because I'm lazy
valuesDF = valuesDF
.withColumn( attribute, regexp_replace(col(attribute), searchValue, replaceValue ))
}
catch {case _: Exception =>
null
}
}
Any ideas? Advice? Thanks.
First, we'll need a function that executes a join of valuesDf with summaryDf by Value and the respective pair of Favourite* and Field:
private def joinByColumn(colName: String, sourceDf: DataFrame): DataFrame = {
sourceDf.as("src") // alias it to help selecting appropriate columns in the result
// the join
.join(summaryDf, $"Value" === col(colName) && $"Field" === colName, "left")
// we do not need the original `Favourite*` column, so drop it
.drop(colName)
// select all previous columns, plus the one that contains the match
.select("src.*", "ValueDesc")
// rename the resulting column to have the name of the source one
.withColumnRenamed("ValueDesc", colName)
}
Now, to produce the target result we can iterate on the names of the columns to match:
val result = Seq("FavouriteBeer",
"FavouriteCheese").foldLeft(valuesDF) {
case(df, colName) => joinByColumn(colName, df)
}
result.show()
+-------------+---------------+
|FavouriteBeer|FavouriteCheese|
+-------------+---------------+
| Unknown| Cheddar|
| Unknown| Emmental|
| InnisAndGunn| Brie|
| Carlsberg| Unknown|
+-------------+---------------+
In case a value from valuesDf does not match with anything in summaryDf, the resulting cell in this solution will contain null. If you want just to replace it with Unknown value, instead of .select and .withColumnRenamed lines above use:
.withColumn(colName, when($"ValueDesc".isNotNull, $"ValueDesc").otherwise(lit("Unknown")))
.select("src.*", colName)

Querying partial value from a field - SQL SERVER 2008

I need to return only a portion of the value in a given field.
Example:
A given field returns something like 'AB-1X3.4567' but the desired value is only the '1X3.4567'portion. So for this example I need to remove anything that precedes the pattern of
[0-9,A-Z][0-9,A-Z][0-9,A-Z][.][0-9,A-Z][0-9,A-Z][0-9,A-Z][0-9,A-Z].
What query could I write to do this?
using stuff() and patindex():
create table t (val varchar(32))
insert into t values
('AB-1X3.4567') -- given example
,('1X3.4567AB-1X3.4567') --extra junk on the end
,('1X3.4567') -- goldy locks
,('X3.4567') -- too short
,('AB-1X#.4567') -- # is not [0-9A-Z]
select
val
, str = stuff(val,1,patindex('%[0-9A-Z][0-9A-Z][0-9A-Z][.][0-9A-Z][0-9A-Z][0-9A-Z][0-9A-Z]%',val)-1,'')
from t
rextester demo: http://rextester.com/ITUJ68634
returns:
+---------------------+---------------------+
| val | str |
+---------------------+---------------------+
| AB-1X3.4567 | 1X3.4567 |
| 1X3.4567AB-1X3.4567 | 1X3.4567AB-1X3.4567 |
| 1X3.4567 | 1X3.4567 |
| X3.4567 | NULL |
| AB-1X#.4567 | NULL |
+---------------------+---------------------+
Your pattern alludes to anything which is XXX.XXXX where X = any single digit or letter. In that case we can use RIGHT() and LEN()
DECLARE #value VARCHAR(4000)='AB-1X3.4567'
SELECT RIGHT(#value,LEN(#value) - 3)

How do you do a "where in" sql query with an array data type?

I have a field:
dtype ==> character varying(3)[]
... but it's an array. So I have for example:
ID | name | dtype
1 | one | {'D10', 'D20', 'D30'}
2 | sam | {'D20'}
3 | jax | {'D10', 'D20'}
4 | pam | {'D10', 'D30'}
5 | pot | {'D10'}
I want to be able to do something like this:
select * from table where dtype in ('D20', 'D30')
This syntax doesnt work, but the goal is to then return fields 1,2,3,4 but not 5.
Is this possible?
Use the && operator as shown in the PostgreSQL manual under "array operators".
select * from table where dtype && ARRAY['D20', 'D30']