t-sql lost contexted - sql-server

Question

I not sure why I'm losing context at FROM #TableName at line 36. I got this code of stack and am trying to change it to output to the screen and not a table. SQL Server Management Studio does not know the variable but does knows that same variable from the line just above it.
DECLARE #TableName nvarchar(256),
#ColumnName nvarchar(128),
#SearchStr2 nvarchar(110)
SET #TableName = ''
SET #SearchStr2 = QUOTENAME('%28217965%','''')
WHILE #TableName IS NOT NULL
BEGIN
SET #ColumnName = ''
SET #TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > #TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped') = 0)
WHILE (#TableName IS NOT NULL) AND (#ColumnName IS NOT NULL)
BEGIN
SET #ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(#TableName, 2)
AND TABLE_NAME = PARSENAME(#TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
AND QUOTENAME(COLUMN_NAME) > #ColumnName
)
IF #ColumnName IS NOT NULL
BEGIN
SELECT #TableName + '.' + #ColumnName, LEFT( #ColumnName, 3630)
FROM #TableName
WHERE #ColumnName + ' LIKE ' + #SearchStr2
END
END
END

Answer 1

SELECT #TableName + '.' + #ColumnName, LEFT( #ColumnName, 3630)
FROM #TableName
WHERE #ColumnName + ' LIKE ' + #SearchStr2
This is not valid T-SQL. #TableName is a scalar variable, not a table variable. You can't use variable table names like this. You'd have to use dynamic SQL to accomplish what you're trying. Take a look at the EXEC() statement.
Try something like:
DECLARE #SQL VARCHAR(MAX);
....
IF #ColumnName IS NOT NULL
BEGIN
SELECT #SQL = 'SELECT ' + #TableName + '.' + #ColumnName + ', LEFT(' +
#ColumnName + ', 3630) FROM ' + #TableName + ' WHERE ' + #ColumnName +
' LIKE ' + #SearchStr2;
EXEC(#SQL);
END
....