How to create a delta table with invalid characters in column headers - databricks

Looking for a work around to create delta table with invalid character (). Below is the example
CREATE TABLE `log` (
`Error_Description` STRING,
`Age(months)` STRING,
`%Role` STRING)
USING Delta
Error in SQL statement: AnalysisException: Attribute name "Age(months)"
contains invalid character(s) among " ,;{}()\n\t=". Please use alias to rename it.

Related

Resolve datatype conflicts with Copy command in databricks

I have a requirement to load the data from a csv file in ADLS Gen2 to Delta table. I am using the copy for the same. One of the column in the target table 'IS_ACTIVE' is defined as TINYINT. When triggering the below code, it fails with the following error.
Failed to merge fields 'IS_ACTIVE' and 'IS_ACTIVE'. Failed to merge incompatible data types ByteType and StringType
COPY INTO metadata.md_config_master
FROM 'abfss://{container}#{storage_account}.dfs.core.windows.net/table_folder/'
WITH (CREDENTIAL (AZURE_SAS_TOKEN = '<sas_token_string>')
)
FILEFORMAT = CSV
FILES = ('MD_CONFIG_MASTER.csv')
FORMAT_OPTIONS ('mergeSchema'='true', 'header' = 'true', 'inferSchema'='true')
COPY_OPTIONS ('force' = 'true', 'mergeSchema'= 'true')
When I did not use 'inferSchema'='true' option in FORMAT_OPTIONS, it was failing due to data type mismatch for a integer column also. when i used 'inferSchema'='true' then this error disappeared.
But still have issue with TINYINT column conversion.
When I create the target table with all string columns, then the command is successful.
Is there a way to make this code run? I did not define ByteType at all in my target table. May be it is considering TINYINT as ByteType. I am not so sure.
Note: I can actually read the ADLS file and create a pandas Dataframe and convert this to spark dataframe and load the data to target table. But that is not what I am looking for. I want this copy command to work. Hence looking for a solution specifically for this COPY command.
Sample Schema:
CREATE TABLE IF NOT EXISTS metadata.MD_CONFIG_MASTER(
CONFIG_ID INT,
CLIENT_NAME STRING,
TARGET_DATABASE STRING,
TARGET_DATABASE_MODULE_NAME STRING,
TARGET_DATABASE_DRIVER_CLASS_NAME STRING,
TARGET_DATABASE_CNX_INFO STRING,
EXECUTION_PLATFORM STRING,
IS_ACTIVE TINYINT,
INSERT_DTS TIMESTAMP
) USING DELTA;
This error occurs when your data has any string values in that column.
I reproduced this with sample data. I have given a string value in Age column.
You can see, I got the same error when tried copy into code.
So, check your data if it has any string values in that column.
When I removed the string value and added the integer value in that column, I am able to copy the data.
Data successfully copied to delta table.

Hive, how to partition by a colum with null values, putting all nulls in one partition

I am using Hive, and the IDE is Hue. I am trying different key combinations to choose for my partition key(s).
The definition of my original table is as follows:
CREATE External Table `my_hive_db`.`my_table`(
`col_id` bigint,
`result_section__col2` string,
`result_section_col3` string ,
`result_section_col4` string,
`result_section_col5` string,
`result_section_col6__label` string,
`result_section_col7__label_id` bigint ,
`result_section_text` string ,
`result_section_unit` string,
`result_section_col` string ,
`result_section_title` string,
`result_section_title_id` bigint,
`col13` string,
`timestamp` bigint,
`date_day` string
)
PARTITIONED BY (
`date_year` string,
`date_month` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
's3a://some/where/in/amazon/s3';
The above code is working properly. But when I create a new table with date_day as partition key, the table is empty and I need to run MSCK Repair Table. However, I am getting the following error:
Error while compiling statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.ddl.DDLTask
When the partion keys were date_year, date_month, MSCK worked properly.
Table definition of the table I am getting the error for is as follows:
CREATE External Table `my_hive_db`.`my_table`(
`col_id` bigint,
`result_section__col2` string,
`result_section_col3` string ,
`result_section_col4` string,
`result_section_col5` string,
`result_section_col6__label` string,
`result_section_col7__label_id` bigint ,
`result_section_text` string ,
`result_section_unit` string,
`result_section_col` string ,
`result_section_title` string,
`result_section_title_id` bigint,
`col13` string,
`timestamp` bigint,
`date_year` string,
`date_month` string
)
PARTITIONED BY (
`date_day` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
's3a://some/where/in/amazon/s3';
After this the following query is empty:
Select * From `my_hive_db`.`my_table` Limit 10;
I therefore ran the following command:
MSCK REPAIR TABLE `my_hive_db`.`my_table`;
And I get the error: Error while compiling statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.ddl.DDLTask
I checked this link as it is exactly the error I am getting, but by using the solution provided:
set hive.msck.path.validation=ignore;
MSCK REPAIR TABLE table_name;
I get a different error:
Error while processing statement: Cannot modify hive.msck.path.validation at runtime. It is not in list of params that are allowed to be modified at runtime.
I think the reason I am getting these errors is that there are more than 200 million records with date_day having null value.
There are 31 distinct date-day not null values. I would like to partition my table with 32 partitions, each for a distinct value of date_day field, and all the null values get into a different partition. Is there a way to do so (partitioning by a column with null values)?
If this can be achieved by spark, I am also open to use it.
This is part of a bigger problem of changing partition keys by recreating a table as mentioned in this link in answer to my other question.
Thank you for your help.
You seem to not understand how Hive's partitioning work.
Hive stores data into files on HDFS (or S3, or some other distributed folders).
If you create a non-partitioned parquet table called my_schema.my_table, you will see in your distributed storage files stored in a folder
hive/warehouse/my_schema.db/my_table/part_00001.parquet
hive/warehouse/my_schema.db/my_table/part_00002.parquet
...
If you create a table partitioned by a column p_col, the files will look like
hive/warehouse/my_schema.db/my_table/p_col=value1/part_00001.parquet
hive/warehouse/my_schema.db/my_table/p_col=value1/part_00002.parquet
...
hive/warehouse/my_schema.db/my_table/p_col=value2/part_00001.parquet
hive/warehouse/my_schema.db/my_table/p_col=value2/part_00002.parquet
...
The command MSCK repair table allows you to automatically reload the partitions, when you create an external table.
Let's say you have folders on s3 that look like this:
hive/warehouse/my_schema.db/my_table/p_col=value1/part_00001.parquet
hive/warehouse/my_schema.db/my_table/p_col=value2/part_00001.parquet
hive/warehouse/my_schema.db/my_table/p_col=value3/part_00001.parquet
You create an external table with
CREATE External Table my_schema.my_table(
... some columns ...
)
PARTITIONED BY (p_col STRING)
the table will be created but empty, because Hive hasn't detected the partitions yet. You run MSCK REPAIR TABLE my_schema.my_table, and Hive will recognize that your partition p_col matches the partitioning scheme on s3 (/p_col=value1/).
From what I could understand from your other question, you are trying to change the partitioning scheme of the table by doing
CREATE External Table my_schema.my_table(
... some columns ...
)
PARTITIONED BY (p_another_col STRING)
and you are getting an error message because p_another_col doesn't match with the column used in s3, which was p_col.
And this error is perfectly normal, since what you are doing doesn't make sense.
As stated in the other question's answer, you need to create a copy of the first table, with a different partitioning scheme.
You should instead try something like this:
CREATE External Table my_hive_db.my_table_2(
`col_id` bigint,
`result_section__col2` string,
`result_section_col3` string ,
`result_section_col4` string,
`result_section_col5` string,
`result_section_col6__label` string,
`result_section_col7__label_id` bigint ,
`result_section_text` string ,
`result_section_unit` string,
`result_section_col` string ,
`result_section_title` string,
`result_section_title_id` bigint,
`col13` string,
`timestamp` bigint,
`date_year` string,
`date_month` string
)
PARTITIONED BY (`date_day` string)
and then populate your new table with dynamic partitioning
INSERT OVERWRITE TABLE my_hive_db.my_table_2 PARTITION(date_day)
SELECT
col_id,
result_section__col2,
result_section_col3,
result_section_col4,
result_section_col5,
result_section_col6__label,
result_section_col7__label_id,
result_section_text,
result_section_unit,
result_section_col,
result_section_title,
result_section_title_id,
col13,
timestamp,
date_year,
date_month,
date_day
FROM my_hive_db.my_table_1

Inserting Timestamp Into Snowflake Using Python 3.8

I have an empty table defined in snowflake as;
CREATE OR REPLACE TABLE db1.schema1.table(
ACCOUNT_ID NUMBER NOT NULL PRIMARY KEY,
PREDICTED_PROBABILITY FLOAT,
TIME_PREDICTED TIMESTAMP
);
And it creates the correct table, which has been checked using desc command in sql. Then using a snowflake python connector we are trying to execute following query;
insert_query = f'INSERT INTO DATA_LAKE.CUSTOMER.ACT_PREDICTED_PROBABILITIES(ACCOUNT_ID, PREDICTED_PROBABILITY, TIME_PREDICTED) VALUES ({accountId}, {risk_score},{ct});'
ctx.cursor().execute(insert_query)
Just before this query the variables are defined, The main challenge is getting the current time stamp written into snowflake. Here the value of ct is defined as;
import datetime
ct = datetime.datetime.now()
print(ct)
2021-04-30 21:54:41.676406
But when we try to execute this INSERT query we get the following errr message;
ProgrammingError: 001003 (42000): SQL compilation error:
syntax error line 1 at position 157 unexpected '21'.
Can I kindly get some help on ow to format the date time value here? Help is appreciated.
In addition to the answer #Lukasz provided you could also think about defining the current_timestamp() as default for the TIME_PREDICTED column:
CREATE OR REPLACE TABLE db1.schema1.table(
ACCOUNT_ID NUMBER NOT NULL PRIMARY KEY,
PREDICTED_PROBABILITY FLOAT,
TIME_PREDICTED TIMESTAMP DEFAULT current_timestamp
);
And then just insert ACCOUNT_ID and PREDICTED_PROBABILITY:
insert_query = f'INSERT INTO DATA_LAKE.CUSTOMER.ACT_PREDICTED_PROBABILITIES(ACCOUNT_ID, PREDICTED_PROBABILITY) VALUES ({accountId}, {risk_score});'
ctx.cursor().execute(insert_query)
It will automatically assign the insert time to TIME_PREDICTED
Educated guess. When performing insert with:
insert_query = f'INSERT INTO ...(ACCOUNT_ID, PREDICTED_PROBABILITY, TIME_PREDICTED)
VALUES ({accountId}, {risk_score},{ct});'
It is a string interpolation. The ct is provided as string representation of datetime, which does not match a timestamp data type, thus error.
I would suggest using proper variable binding instead:
ctx.cursor().execute("INSERT INTO DATA_LAKE.CUSTOMER.ACT_PREDICTED_PROBABILITIES "
"(ACCOUNT_ID, PREDICTED_PROBABILITY, TIME_PREDICTED) "
"VALUES(:1, :2, :3)",
(accountId,
risk_score,
("TIMESTAMP_LTZ", ct)
)
);
Avoid SQL Injection Attacks
Avoid binding data using Python’s formatting function because you risk SQL injection. For example:
# Binding data (UNSAFE EXAMPLE)
con.cursor().execute(
"INSERT INTO testtable(col1, col2) "
"VALUES({col1}, '{col2}')".format(
col1=789,
col2='test string3')
)
Instead, store the values in variables, check those values (for example, by looking for suspicious semicolons inside strings), and then bind the parameters using qmark or numeric binding style.
You forgot to place the quotes before and after the {ct}. The code should be :
insert_query = "INSERT INTO DATA_LAKE.CUSTOMER.ACT_PREDICTED_PROBABILITIES(ACCOUNT_ID, PREDICTED_PROBABILITY, TIME_PREDICTED) VALUES ({accountId}, {risk_score},'{ct}');".format(accountId=accountId,risk_score=risk_score,ct=ct)
ctx.cursor().execute(insert_query)

Why AWS Athena returns "string" datatype to all table's fields on "show create table" command or describe tables

Why AWS Athena returns "string" datatype to all table's fields on
"show create table" command or on describe tables:
for example table t_mus_albums:
albumid (bigint)
title (string)
artistid (bigint)
whan running
show create table t_mus_albums;
I get:
CREATE EXTERNAL TABLE `t_mus_albums`(
`albumid` string COMMENT 'from deserializer',
`title` string COMMENT 'from deserializer',
`artistid` string COMMENT 'from deserializer')
I think you might be doing something wrong or while generating the table automatically, you may not have correct formatted data.
Here are the systematic steps to solve your problem.
Assume that your data is in below format.
ID,Code,City,State
41,5,"Youngstown", OH
42,52,"Yankton", SD
46,35,"Yakima", WA
42,16,"Worcester", MA
43,37,"Wisconsin Dells", WI
36,5,"Winston-Salem", NC
Then your create table will go something like below.
CREATE EXTERNAL TABLE IF NOT EXISTS example.tbl_datatype (
`id` int,
`code` int,
`city` string,
`state` string
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
WITH SERDEPROPERTIES (
'serialization.format' = ',',
'field.delim' = ','
) LOCATION 's3://example-bucket/location/a/'
TBLPROPERTIES ('has_encrypted_data'='false');
Then, run the Query to description the table.
SHOW CREATE TABLE tbl_datatype;
It will give you output something like below.
CREATE EXTERNAL TABLE `tbl_datatype`(
`id` int,
`code` int,
`city` string,
`state` string)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ','
STORED AS INPUTFORMAT
'org.apache.hadoop.mapred.TextInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'
LOCATION
's3://example-bucket/location/a/';
Hope it helps!
This is because you use CSV serde and not e.g. TEXT serde.
CSV serde does support only string data type, so all columns are of this type.
From https://docs.aws.amazon.com/athena/latest/ug/csv.html
The OpenCSV SerDe [...] Converts all column type values to STRING.
The documentation outlines some conditions under which the table schema could be different than all strings ("For example, it parses the values into BOOLEAN, BIGINT, INT, and DOUBLE data types when it can discern them"), but apparently this was not effective in your case.

Turning a Comma Separated string into individual rows in Teradata

I read the post:
Turning a Comma Separated string into individual rows
And really like the solution:
SELECT A.OtherID,
Split.a.value('.', 'VARCHAR(100)') AS Data
FROM
( SELECT OtherID,
CAST ('<M>' + REPLACE(Data, ',', '</M><M>') + '</M>' AS XML) AS Data
FROM Table1
) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);
But it did not work when I tried to apply the method in Teradata for a similar question. Here is the summarized error code:
select failed 3707: expected something between '.' and the 'value' keyword. So is the code only valid in SQL Server? Would anyone help me to make it work in Teradata or SAS SQL? Your help will be really appreciated!
This is SQL Server syntax.
In Teradata there's a table UDF named STRTOK_SPLIT_TO_TABLE,
e.g.
SELECT * FROM dbc.DatabasesV AS db
JOIN
(
SELECT token AS DatabaseName, tokennum
FROM TABLE (STRTOK_SPLIT_TO_TABLE(1, 'dbc,systemfe', ',')
RETURNS (outkey INTEGER,
tokennum INTEGER,
token VARCHAR(128) CHARACTER SET UNICODE)
) AS d
) AS dt
ON db.DatabaseName = dt.DatabaseName
ORDER BY tokennum;
Or see my answer to this similar question

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